Los Angeles
So you're no Mrs. Robinson, eh? 
I keep recommending West LA whenever this question comes up because:
1.) That's where most of the white-collar jobs are concentrated these days, so that's where you'll find the largest number of men who can afford this hobby. Investment bankers, fund managers, attorneys, agents, doctors - the best ones are all in WLA (basically anywhere west of La Brea Ave.)
2.) Traffic is insane, so if you go anywhere else, people will be reluctant to drive there.
3.) Yes, you will be competing with the best of the best in WLA, but that's where all the action is, and not all of the players want a 20-something hottie. (I do, but that's a separate topic!)
4.) If business is slow, there are lots of other fun things to do in WLA. Not as many cool places to hang out if you are near LAX, Downtown L.A., the Valley, South Bay, etc.
So you're no Mrs. Robinson, eh?
I keep recommending West LA whenever this question comes up because:
1.) That's where most of the white-collar jobs are concentrated these days, so that's where you'll find the largest number of men who can afford this hobby. Investment bankers, fund managers, attorneys, agents, doctors - the best ones are all in WLA (basically anywhere west of La Brea Ave.)
2.) Traffic is insane, so if you go anywhere else, people will be reluctant to drive there.
3.) Yes, you will be competing with the best of the best in WLA, but that's where all the action is, and not all of the players want a 20-something hottie. (I do, but that's a separate topic!)
4.) If business is slow, there are lots of other fun things to do in WLA. Not as many cool places to hang out if you are near LAX, Downtown L.A., the Valley, South Bay, etc.