Because I've largely stopped buying older games for a while (over a year now), it's not something I've thought about much recently. Let's see... Not sure there's even 10 that I really really want.
No particular order:
Little Samson (I skipped MANY copies when the game was "worth" 100$ because I thought it was too expensive... whoops
Wouldn't mind the japanese version, of course)
Magical Pop'n (Super Famicom games aren't easy to come by already, let alone one that seems rarer)
Wild Guns
Banjo-Tooie
Fire 'N Ice
Holy Diver
Ninja Warriors
Paper Mario: The Thousand-Year Door
... Yeah, that's about all that I can think of right now that I'll totally go for if I find them for a good price. And I'm super picky with my prices. There's other games I wouldn't mind, but they're not terribly important.
... I need to empty out that wishlist some, there's lots of stuff on there I don't really want anymore