"Stocking a Dungeon for Fun and Profit" at ICS (Iuz Correspondence Schools).
Actually, If I had to pick a "worst," it would be the Psion, due to the dependency on each stat to determine the strength of his powers, and what powers he could use at high level. Although it gives them a unique flavor, it is quite crippling above 8th level or so, because the higher your level, the more limited your pool of powers to choose from.
I voted for the ranger....the standard 3e ranger is so badly designed as to be barely viable...a chunk of stuff at 1st level...most of which I dont see what it has to do with the class...and then nothing.
My second choice would be Sorcerer. the standard sorcerer is viable..but barely...and if you try to make something other than a cannon with it it because questionable.
I dont think the Bard is as bad as some say...but it does need work...I believe it will be truly great with 3er.
I went with concept vs execution myself and picked bard. Ranger is about as bad, but I like the concept of a bard so much that the execution sticks in my craw worse...