Hmm.... lets see
Super Mario Brothers 3 (NES) - might be the most well known game on the NES (trailing maybe SMB/Duck Hunt.) Definitely a masterpiece.
Final Fantasy 7 (PSX)- the only FF (besides Tactics) that I actually ended up liking once the game was beaten. I'm guessing this si because of the story, all of the other FFs had some kind of excitement lapse in the middle (err... or just a period where nothing was really happening in the story, even as part of the story) And no, I haven't completed 6 or below yet.
Street Fighter Alpha 3 (PSX)- possibly the best of the SF series (although SF2 is known the most) A plethora of characters and one of (imo) the funnest 2D fghting games.
Resident Evil (PSX... and Gamecube, though they aren't really the same games.) - as some of you know, I like the RE series... a bit too much... so of course I had to put this on here. Not the first game of its genre, but its the most well-known for marking the survival horror cliche' on modern systems.
Monster Rancher 2 (PSX) - Okay, this is the most less known of the rest, but its also more on "Games I Enjoyed" rather than "Best games ever."(Yes, I didn't list these games just because I liked them)
It's the only MR game I could ever get into after they brought the horrid Bookawhatchamacallit system so you can automatically get the creatures from the file instead of putting the CD in every time. I rather enjoyed digging through every CD I have (1000+) digging for the right one. Crazy? Possibly.