this is a fairly broad question, so I'll ignore it and just use it as an excuse to bring up my three favourite ports of the past few years - which just happen to be M2 ported sega games
- Outrun: 60fps outrun on a nice display. Doesn't have the cd arrangements of the saturn version but outrun doesn't really need that, and man it's just fun to play
- Virtua Racing: oooh geez, virtua racing has never looked this good before. silky smooth 60fps port running at HD. the game is still the same it ever was, nothing added. but it's really a joy to play now
- Phantasy Star 1: it's a shame the other games didn't get the treatment the first one did, but the quality of life improvements make this the default choice for playing Phantasy Star now. dungeon mapping so you can figure out where you are without a guide and easy access to manual stuff, great time.