Ripper, by Stefan Petrucha

Orphan Carver Young has some general fantasies about becoming a detective, and devours novels and stories about  great sleuths, as well as serialized and sensationalized mysteries.  When ex-Pinkerton Detective Albert Hawking, cranky, contentious, eccentric, brilliant, and crippled, offers to take Carver on as an apprentice to share all he knows, Carver is ecstatic, even though it means living (for a reason I never really understood) in a private floor at the top of a mental institution, and getting more questions, half-hints, and criticism from Hawking than direct answers.  Carver's first and main "case" is to figure out the identity and possibly location of his father based on a scrap of a letter sent to the orphanage many years before.  As part of this Hawking introduces him to the "New Pinkertons", an underground (literally) and top-secret detective agency endowed by Alan Pinkerton upon his death. Hawking was head of the agency until his injuries forced him to give the reins to another former Pinkerton agent, Tudd, who is devoted to "gadgets" and buys many, many new mechanical, electrical inventions to help the secret agents with their investigations, and who is obsessed with catching a murderer, convinced it is the return of Jack the Ripper.

Ruby Red by Kerstin Gier

1st in Ruby Red series.  Sequel is Sapphire Blue.  First published in Germany.

Gwen is 16 and lives with her mum, siblings, grandmother, aunt and cousin in an upperclass London neighborhood.  Her extended family doesn't pay much attention to her, focused on her cousin, believed to be the carrier of the time-travel gene that runs through her family and sure to show up very soon in the form of an abrupt trip to somewhere in the past.  But all is not as it seems.  Since a mathematical formula had worked out that Gwen's real birth  date was the birth date of the next time traveler, and her cousin was also born that day, Gwen's mum and (late) father secretly falsified her records to indicate Gwen was born the day before, allegedly in the hopes that she would be able to live a normal life (and since she was born at home with a midwife, no one was the wiser.

The Book of Blood and Shadow by Robin Wasserman

Nora has a pretty good life - yes, her brother is still dead and her parents are still withdrawn into their own self-absorbed worlds, but she has made a new family of sorts, with bright, charming, boy-wonder Chris and his lovely, capricious girlfriend Adriane as her best friends, and moody, quiet, scholarly Max as her boyfriend.  She also has an engrossing translation project for a local professor to strengthen her link with Chris and Max - while they work on translating the "important" parts of an ancient mystical document the professor is obsessed with, Nora translates late 16th century letters from a young woman, stepdaughter to a great magician - busy work to the professor, but more and more fascinating to Nora.  When her translation of the letters leads to a new discovery, she never expects it to end with the professor insane, Chris dead, Adriane catatonic and Max gone and branded a murder...but that's what happens.

Insurgent by Veronica Roth

Sequel to Divergent

Tris, now on the run as war erupts, attempts to figure out what information is so vital, or so dangerous, that some factions would destroy others just to contain it.  

Divergent by Veronica Roth

In dystopian Chicago, society has been divided into 5 factions, each dedicated to cultivating a certain value:

• Amity (the peaceful)
• Candor (the honest)
• Abnegation (the selfless)
• Erudite (the intelligent)
• Dauntless (the brave) 

Scarlet by A.C. Gaughen

The early days of the Robin Hood story, told from the perspective of "Will" Scarlet.  Known to Robin, John, and a few others as just Scarlet, she is a young woman posing as a young man after running away from an arranged marriage.

Crossed, by Allie Condie

Sequel to Matched.

Ready Player One, by Ernest Cline

Lots and lots and LOTS of geek and pop culture references from the 80's, as a teenage boy and his cohorts/competition attempt to solve puzzles in an online game that will determine who controls the internet in a futuristic society that lives mainly online.  Full summary from the publisher after the break.  Good for advanced teens and adults interested in the tagged subjects.  2011.

The Agency: A Spy in the House, by Y.S. Lee, Bk 1

The Poison Eaters, by Holly Black

The False Princess by Eilis O'Neal

Nalia spends the first 16 years of her life thinking she is the princess and heir to the throne of Thorvald, only to be told that she was only a decoy, switched at birth with the real princess to try to avoid a prophecy made during the queen's pregnancy that the princess would be murdered horribly before her 16th birthday.  The king and queen, having averted their real daughter's death, send the false princess, named Sinda at birth, unceremoniously away from the castle to live in a small village with her only living relative, an aunt who is less than delighted to have a fully grown niece with no domestic skills sprung on her with no means of support.

Please Ignore Vera Dietz, by A. S. King.

This book evoked mixed feelings in several friends, but overall, I liked it.  Vera seemed pretty realistic in terms of not wanting to/not being able to talk about her feelings about her mom leaving, her dad withdrawing and especially her best friend's abandonment and then death.  She also seemed realistic in her self-destructive behavior, needing an outlet for the things she couldn't figure out how to express otherwise.  My main quibble is that Vera seemed to get over her dabbling with alcohol pretty easily - maybe she wasn't a full-fledged alcoholic, but she was definitely using it as a crutch, and that need seemed to evaporate after getting blotto and beaten up at the work Christmas party.  That struck me as a pat way of dealing with her developing problem.

The Rise of Renegade X, by Chelsea M. Campbell

Damien Locke is all set for his 16th birthday - it's the day his life of crime officially begins.  It's basically a technicality - Damien's mom is the mad scientist Mistress of Mayhem, he is a shoe-in for Vilmore Academy, the ultimate school for teenage supervillains and he's already got his supervillain name picked out: Midnight Marauder.  But in Golden City, all supers have a letter appear on their hand on their 16th birthday to make it official - H for heroes and V for villains.  So imagine Damien's surprise when his V doesn't show up, but neither does an H; an X appears instead.

Paranormalcy, by Kiersten White

One in a spate of paranormal-themed YA books, this one held my interest more than many of the others I've read lately.  Evie is a teen who has been fostered with the International Paranormal Containment Agency since she was 8 years old, working for them during that time as the only person able to see through any glamour from any paranormal.  It's not breaking new ground in terms of content or teen angst, but it does have some nice "surprises". 

Only the Good Spy Young, by Ally Carter, Bk 4 in the Gallagher Girls series

In the previous three books in the series Cammie aka Chameleon Morgan has found out how serious being a Gallagher Girl is.  In the beginning it was fun knowing that she was a spy-in-training, sneaking out to meet a townie boy in Book 1 and using their special skills at detection, evasion, invention and deception to learn more about the mysterious boys from Blackthorne Academy in Book 2. 

Incarceron, by Catherine Fisher

Finn is a "cell-born" member of a Scum gang in Incarceron, the living prison with millions of electronic eyes and torture chambers, designed to recycled and re-use everything, even the people who are imprisoned there.  Finn remembers nothing before waking up in a cell, apparently remade from DNA of others who died, but his flashes of memory of the outside world convince him that he belongs outside.

White Cat by Holly Black, Curse Workers, Bk. 1

It was extremely hard not to read ahead in this book because I wanted to know what was going to happen next.  Little clues and pieces of info get scattered out like breadcrumbs, drawing you on, making you want to keep reading.  I figured out some of the twists before they came, but not all, and not too much before they were revealed.

It's a Mall World After All by Janette Rallison

Charlotte has a grudge against her best friend's boyfriend because of how he treated her in middle school, teasing her and making her life miserable.  As seniors now, Charlotte is convinced that Bryant is cheating on Brianna, and spies on him to prove it.  Instead of finding hard evidence of cheating, she keeps getting herself in embarrassing (and messy) situations, usually involving Colton, a guy in many of her classes, president of the National Honor Society club she belongs to, and also the guy who is Bryant's best friend and convinced he isn't cheating.  Charlotte has to face her own prejudices against Bryant and hope Colton and Brianna can get past their preconceived notions of Bryant's honesty in a light and fluffy book about high school and friendships.  A sub-plot in which Charlotte helps a little boy get shoes for his mom by organizing a Christmas gift drive offers some real heart, and Rallison's writing offers real opportunities for laughing out loud.

SLJ recommendation for grades 6-10

The Disreputable History of Frankie Landau Banks by E. Lockhart

Frankie has her growth spurt and discovers leave-in conditioner the summer after her freshman year in high school, and when she gets back to school, boys seem to notice.  In particular one boy, Matthew, whom Frankie begins to date.  But Matthew and his friends are part of a secret society, the Basset Hounds, and the society doesn't let in girls.  Frankie, frustrated at being underestimated, impersonates the Basset's leader, organizing increasingly daring and successful pranks on campus, but pulling off brilliant pranks while letting someone else gets the credit rankles, and ultimately she has to come clean.  There are elements of romance, but ultimately this story is about Frankie and her growing realization of how being female effects how others see and treat her.  It doesn't have a "happy ending" in that Frankie does not end up with the boy of her dreams, but she does recognize her own self-confidence, worth and sense of power.

One Night That Changes Everything by Lauren Barnholdt

Eliza is looking forward to a quiet night watching movies with her best friends while her parents are out of town, but a club of boys from her school, including the ex-boyfriend that only dated her as initiation into the club, use her notebook of secret things to blackmail her into doing stunts around Boston. Includes under-age drinking, references to drugs and sex that might make some teens (and unparents) uncomfortable, but the overall message doesn't glorify any of them. The relationships with best friends are depicted pretty realistically (both friends get distracted by their own concerns - other friends, boys, etc. - but pull together for Eliza when she needs them most. A touch of romance, a supportive relationship with her older sister, and the thrill and danger of staying out all night will appeal to teen readers, probably of the female variety.

My recommendation - 9th grade and up.