All the GB/GBC/GBA Zeldas, Mystic Quest (GB), Mario Land 2 (GB), Rastan (MS), Golden Axe (MD), Colin McRae (PS1), G Darius (PS1), Sagaia (MS), Nemesis (GB), Solar Striker (GB).
There's loads more, I have a thing for original GB games so they usually get preference!
EDIT Forgot all the Metroidvanias, how could I leave out those? Everything from SotN up to the first 2 DS ones will keep me entertained for hours.