Not only Mega Man X2 is the best MMX game for me, but it's also my favorite MM game of all time.
Gameplay: Capcom has never blew it with the gameplay. Sure, it's the same gameplay as it's predecessor, but it's still masterful in every way possible. You can jump, shoot normal/charge shots with your Buster, dash, wall kick, find upgrades, and get extra weapons from defeated Mavericks. The Mavericks in the game are Wire Sponge, Morph Moth, Flame Stag, Magna Centipede, Overdrive Ostritch, Bubble Crab, Wheel Gator, and Crystal Snail. Once you beat two Mavericks, you can now fight the X-Hunters to get Zero's parts. The X-Hunters are Serges, Violen, and Agile. They can be found on random stages, depending on what stages you have beaten. You can get one of two separate endings, depending on whether or not you get all three Zero's parts. Like all the other Mega Man X games, MMX2 has different body upgrades for X. The Leg Upgrade enables X to air dash. The Helmet Upgrade enables X to see things never saw in a stage. The Body Upgrade lets X do an Explosion attack, which damages all enemies on screen. The X-Buster Upgrade lets X charge his special weapons, as well as doing a Double Charge Shot. The first shot is a green/blue charge shot. The second shot is a pink shot with blue side-blasts. Personally, the Double Charge Shot is my favorite X-Buster Upgrade. As a result, the gameplay is fantastic.
Graphics: Very good for a Super Nintendo game. All the sprites animate top-notch, and the work of the Capcom C4 Graphics Chip was a nice touch.
Sound: Again, MMX2 has very good sound quality. The game's sound effects are superb, and the music is very decent.
Value: I dunno, I'll just say that this game is pretty addictive because of more bosses and great replayability. (I'm not that good in the Value Attribute)
Tilt: Overall, not only Mega Man X2 is the best MMX game for me, but it's also my favorite MM game of all time. I highly recommend this game to SNES owners and Mega Man fans.