[D&D 3.5] What if...we banned the Player's Handbook?

(PHB 2)
Beguiler - My favourite class ever. Enough magic to be useful but not game-breaking, and plenty of skills.
Dragon Shaman - Interesting fluff but lacks power in any one area.
Duskblade - Great melee fighter and lots of spells.
Knight - This is why the "tank" role really doesn't work in 3.5.

(Complete Divine)
Favored Soul - Good spell list but ridiculously lame class features. PrC ASAP, or check the Pathfinder Oracle instead.
Shugenja - Might be interesting but no one has ever played one. Not even once.
Spirit Shaman - Makes good use of druid spell list. Class features are okay.

(Complete Warrior)
Hexblade - Potent if built right. Author published an unofficial errata which buffs the class a bit.
Samurai - Awful, awful class design. Did I mention it was awful.
Swashbuckler - Fun in theory but lacks any worthwhile class features after level 3.

(Complete Adventurer)
Ninja - Eventually you'll be invisible all the time.
Scout - Skirmish is easier to exploit than sneak attack. Class features are a little stronger than rogue's.
Spellthief - Interesting in theory but suffers badly from MAD. Struggles at low levels.

(Complete Arcane)
Warlock - Consensus is that it needs more invocations known. Level/2 * 1d6 damage at will is very potent for most non-optimized games.
Warmage - This is why the "blaster" role really doesn't work in 3.5, at least as well as other roles.
Wu Jen - Basically a wizard with less splatbook support.

(Heroes of Horror)
Archivist - Easily able to exploit spells found on obscure class lists. If you are prepared for this, the class features are a lot of fun.
Dread Necromancer - Good class. Make arrangements with the player, if they ever say, "hold on, I need to look up the stats for that," you get to punch them in the shoulder.

(Eberron Campaign Setting)
Artificer - Either too ineffective or game-breaking. Very hard to find a balance.

(Dragon Magic)
Dragonfire Adept - Similar to warlock. Slightly better than dragon shaman.

(Dungeonscape)
Factotum - Lots of fun. Game-breaking by exploit-happy players so be aware of this.

(Miniatures Handbook)
Healer - This is why the "healer" role really doesn't work in 3.5. D&D is not an MMORPG.
Marshal - Helpful to party, but oh so boring to play in combat.

(Tome of Magic)
Binder - Great fluff. Well-balanced. Fun to play and roleplay. Great class.
Shadowcaster - This is why splatbook support is the difference between a decent class and an uber one. Class designer published an unofficial errata which boosts it a bit, but keeps it out of game-breaking territory.
Truenamer - OH GAWD MAH BALLS

(Book of Weeaboo Fightan Magic)
Crusader - The middle one. Watch out for White Raven Tactics.
Swordsage - The weaker one.
Warblade - The stronger one. Watch out for Iron Heart Surge.
Overall: Controversial book. Yes, none of them are as powerful as a well-built wizard, but a wizard takes time and knowledge to build right, whereas ToB classes are at roughly their power ceiling right off the bat. Get ready for some ridiculous damage numbers. This is easy to mitigate, but you might not want to have to alter your campaign due to this. Me, I'd just say no.

(Expanted Psionics Handbook)
Psion - On par with sorcerer. Easier to pump out high damage, but lower optimization ceiling.
Psychic Warrior - About the same as psion.
Soulknife - Not as bad as everyone seems to think... as long as everything you fight has an Intelligence score and isn't immune to critical hits. Otherwise, prepare for frustration.
Wilder - Slightly more raw power than psion, but much less versatile.

(Complete Psionic)
Ardent - On par with psion and wilder. The main appeal of the class is that you can have access to high-level powers even if you multiclass, due to the way the class is designed. This can be deadly in the right hands, so be aware of this is you have one in your game. Don't be afraid to just say no.
Divine Mind - Jack of no trades. Gains a stroke of adequacy with online support.
Lurk - Google "psychic rogue." Less gimmicky than this class but about the same amount of power. Plus trapfinding, which you'll be expected to have. Or just add trapfinding to the lurk, which it should have anyway.

(Magic of Incarnum)
Incarnate - Actual jack of all trades class. Functions best as skillmonkey.
Soulborn - Supposed to be awful.
Totemist - Get ready for an absurd mass of natural attacks, combined with pounce. Make sure you are okay with this "Tasmanian Devil" style.
Overall: Mechanically good book, stupid stupid fluff. "Soul power." That's about it. No surprising abilities, though, so odds are it won't break the game.