In the absence of a "Whatever character the player thinks would be the most fun" option, I was forced to select the one
I think is the most fun: the Rogue. (I am, incidentally, an expert in fun: so if your ability to make a decision is permanently impaired for some reason, you may take my advice and be assured that it will serve you well.

)
Of course, I like monks just fine; they're an interesting utility-fighter, and you can do quite a bit with them. The 3.5 version looks better than the 3.0 version, thanks to changes in how damage resistance was handled, but even the 3.0 monk was a fun little class. We've got a monk in our Scarred Lands game, and of all the characters in the party, he's the most interesting one to interact with. When a monk is played well, they can be very memorable.
But for my money, Rogue's the only way to go. They're just such flexible little monkeys, able to do scouting, trap disarming, negotiations, infiltrations, fill a second-string combat position, use all kinds of magic items, and so on, that I was never at a loss when trying to imagine what my character would want out of a situation, and I never felt bored or useless.
--
so unless you suddenly notice you're not me, it looks like rogue is the answer

ryan