Devil May Cry 1, 2, 3, 4, and DMC
Tomba! (cause even if 2 games isn't a series, I wanted it to be...)
Crash Bandicoot as of the PS2 era
Phantasy Star (as of PSPortable 2)
And Mother 1,2, and 3
Legend of Zelda would be awesome to do... that'd be one grand scale marathon though.