Clockwise from the right (yes, clockwise because for the confusionz)
Super Mario Bros.: This one should be obvious, duh. A timeless classic that's still fun to replay on emulators from time to time. Not much to say here apart from the fact that I would beat the game with the "short route" (you know, 4-2 second warp zone) just for fun.
Super Bomberman: I enjoyed this one's single player more than any other Bomberman game, even more than perhaps the "most popular" Bomberman title, Bomberman 64. The ability to kick bombs into enemies to kill them is satisfying, albeit overpowered. Shame that this particular mechanic was never implemented in any future Super Bomberman games. And I just realized this is the only non-platformer on this list (Contra kinda counts as a platformer).
Pac-Man World: A very nostalgic game of mine, though the difficulty and level design can get unfair and frustrating at times (looking at you, the level "Spin Dizzy"). Of course, just about every future Pac-Man games include an emulation of sorts of the original arcade game (or at least some variation of it), this one's not an exception.
Ape Escape: Another nostalgic title of mine, but it's sadly rather unpopular. The unique controls and mechanics are what makes this a great game that didn't get the attention it deserves. It definitely is one of my favorite games.
SpongeBob SquarePants: Battle for Bikini Bottom: The only sixth-generation game here, because many of my other most favorite sixth-gen games were part of a franchise that's already on this list. A licensed game, but yet another one of my highly nostalgic games with nice controls/camera and a large variety of tasks (it's a collect-a-thon), and levels true to the show itself (before it went downhill of course).
Contra: A game I find to be extremely fun especially when I'm going for beating the game without losing a life (in other words, Konami code won't help). I've never accomplished that yet. Also, it's not as hard as most people claim it to be, or am I just better at it?
Spyro the Dragon 2: Ripto's Rage: This is still my favorite of the Spyro trilogy, maybe it's because the nostalgia is stronger with this one. Third game's also fun, and the first game is rather different. It's one of the few games I bothered for 100% completion, because I just love it.
Sonic the Hedgehog: This one's also pretty obvious anyway. It's the only Genesis title here. I'm not exactly a big Sonic fan, but it's always fun to play this at times and try to get all the Chaos Emeralds.
And the middle title because I knew clockwise was a stupid idea:
Crash Bandicoot: Yes, the original Crash Bandicoot. I honestly prefer it over the next two games because I've became so used to the "slippery" controls to the point that I find the "improved" physics of the next two games to be worse. I love the challenge of beating the levels without dying to get the gems. It probably didn't age well for its controls, but do we really need analog sticks for this?
Not gonna include honorable mentions because it'll end up being filled with stuff like Super Mario 64 or the other Crash Bandicoot games.
And no, even for a PlayStation guy like me, FF7 wasn't going to be an honorable mention. That'll be the next two games.