I much prefer to be a PC myself, instead of the GM.
I'm still calling myself a new GM, even though i've been running a Warhammer Fantasy (2nd ed) campaign for almost 2 years. I'm just not real comfortable with it... But sometimes, if you want to play something specific, you'll have to step up and be the GM.
I like drawing maps and NPCs and such, but I'd much rather be making them for someone elses campaign than my own
There's no choice in either campaign for me though. I'm the only one of the people I play with, that wants to be GM in those systems - and I already have the books, soeh.. =)