My favorite Young Adult books from 2011, in no particular order:
Anna and the French Kiss and Lola and the Boy Next Door by Stephanie Perkins
Side note: I totally didn't think I would enjoy these based on the covers. Contemporary YA that isn't dealing with an "issue" isn't my thing. But both of these books were among my favorites this year - they are adorable.
Divergent by Veronica Roth
The Sky is Everywhere by Jandy Nelson
Sweetly by Jackson Pearce
The Way We Fall by Megan Crewe (technically this is a 2012 release, but I read an ARC this year and loved it)