depends on the look you're shooting for. If you want to look like the stereotypical "cool guy" (which WILL pull a lot of chicks) then go with the Abercrombie, Hollister, American Eagle look.
If you're looking for something slightly less generic, I like Express, Izod and Lacoste polos, and a lot of the brand names at Macy's (Perry Ellis, etc.). These are all a bit more formal.
I couldn't tell you where to go for goth clothing, if you're looking to pull those chicks. I have no clue.