I pretty much just emulate games for consoles (home or handheld) that I don't own, and even then it's basically SNES, N64 (sort of but not really) and GB/GBA games. I would prefer to eventually get said consoles though.
Mainly a SNES & N64 anyway. Handheld wise I probably wouldn't look for a used GBA, I'd probably just look for a normal DS since it's backwards compatible with GBA games. Though at the same time, I'd really have to give a long hard look at the games I'd want for the consoles. I couldn't justify forking out all that money when it turns out I only want a handful of games per console. Hence why emulation can be handy.
That said, I'll never emulate PS1 games, despite some friends suggesting it to play certain Final Fantasy games. lol. I'll just see if a store chain called Gametraders has a copy going around that I could get first. Or even try the PSN store thing once I get a PS4 pending the games.
Though, I must say, if Sony decided to make an Ape Escape trilogy HD remake? Fuck buying a used copy of Ape Escape 1, I'd just get the HD remake thing. lol.