Fenros said:
To this, I give my common Munchkin rallying cry; "Can I play a dragon? Please? It'd be a great role-playing stretch for me".
Munchkins are quick to trumpet role-playing to cover their habits. And while I'm not going to go as far as to say that real role-players only stick to first level commoners, in my experience they're more likely to pick a "basic" character than a far out one. And leaving the gates wide open just allows the bad players to give the hard concepts a bad name.
I have a feeling the thread will degenerate after I say this, but my rule on far out races is very much the same as that for playing someone with a different gender, sexual preference, or sometimes even culture than the player. (Before you flame me on that last one, I know someone who after the Ninja's handbook came out, had every character as "you know those asian guys who look white" and acted like any other munchkin out there. I'm far more lenient when culture/ethnicity doesn't bring any kewl p0werz into the mix.)
My rule is pretty simple. Prove to me that you can get into the head of a "normal" PHB character well, and I'll be receptive. Play all your fighter types as "grr me bash" and all your wizards as a pipe, floppy hat, and fireballs, and I won't give you the chance to reduce anyone else into a bad accent, unrealistic genetalia, rampant greed, and/or insulting stereotypes. Deal?
(And I hate to say this, but my default expectation for incoming players is munchkin. I'll just say that I have my reasons.)