Lex Trent Vs. the Gods [Proof] by Alex Bell = Not bad, a reasonable read and some good ideas - but really, go and read Terry Pratchett.
Moist Von Lipwig is a much more likable, fun and dangerous sort of character than Lex who at 17 is mostly just annoying. It remains to be seen if this book will be popular - the crit on the Proof mentioned Terry Pratchett in comparison. There is no comparison. He is smart and witty and awesome. This book not so much (although the ladders were rather intriging).