I'd vote for the legalization of prostitution, marijuana, and opium dens. (heh)
Seriously, I'd probably never visit a brothel. Not for moral reasons, but just because I can always find something more interesting to... er... blow my wad on. 😉
I'm a firm believer in once something stops being novel, and risky, it loses the bulk of its appeal.
I'd bet money that if the government outlawed the use of oxygen bars, they'd STILL be around! 😉