I find it interesting that there is a noticeable number of people that seem to dispise the knight and Dragon shaman (really, i don't have any problem with either class, i've DM'd them both, and played one)
However, out of all books provided, I see that the PHBII is possibly the strongest contender to keep all of it's pieces in the game! Look at the classes voted out this far, by their books!
Complete warrior: 1
Complete arcane: 1
Complete Adventurer: 1
Miniatures handbook: 2
Tome of Magic: 1
Complete Psionic: 1
books not yet touched:
Heroes of Horror: (2 entrants)
Eberron Campaign Setting: (1 entrant)
Players Handbook II: (4 entrants)
Complete Divine: (3 entrants)
Magic of Incarnum (but they are beginning to go this round)
Expanded Psionic (Also going this round)
Hmm... you know, now that I see it again, I fear not enough people know Heroes of Horror to get a proper grasp on their two base classes. and with only one entry, an eberron artificer elimination would completely eliminate their book.