the tux/suit, methinks. i guess thats just because it could make a good first impression (assuming people dont think you might be too organized in a weak way, if that makes sense). plus, in my personal opinion, it attracts the best kind of girls, hehe. (or guys if youre a girl) :o
I would rather wear a tuxedo/suit. Sure, dressing up (especially in black) always makes me self-conscious, because black is like a hair-magnet, but wearing a swim suit everywhere? That's just weird.