In movie sequels, generally, everything after part II sucks (and often times, everything after part I). Video games are different. They can have great sequels way the fuck down the line (see Zelda). This thread I want to dedicate to all the "Part II" sequels, IE the very first sequel. Games where Part II is as far as they got are fair game. I want to exclude part III's and beyond because, like I said, unlike in movies, video game sequels can be great way down the line, so including all the sequels could result in way too long lists.
So anyway, what are your best Part II's?
Mine:
Mega Man 2 (NES)
Mega Man X2 (SNES)
Castlevania II (NES)
Earthworm Jim 2 (SNES)
Street Fighter II (Arcade, various) (arguably the most successful part II of all time relative to part I).
Mario Kart 64 (N64)
Honorable mentions:
Zelda II (NES)
Metroid II (Game Boy)