Taking everyone by complete surprise, this game is the absolute definitive version of Street Fighter II.
The graphics and sound aren't the only aspects to have received HD Remixes. Gameplay wise, HD Remix has been tweaked slightly to be a little more accessible and even out the balancing even more (which is an insanely commendable feat considering how well balanced the original Super II Turbo is). Whether it's giving certain moves slightly higher or lower priority (Vega's wall jump attacks), a new property (Chun-li's Spinning Bird Kick and E. Honda's Head But) or simply changing the input commands to make them easier to execute (Guile's Super Combo!!), slight changes like these make the difference in heated battle and make this the best playing Street Fighter II ever! That sentiment, however, isn't shared universally, so for those purists out there, you have the chance to play in classic mode which not only allows you to play in gameplay perfect original SSFII Turbo mode, but also in gameplay perfect Super Street Fighter II mode, all still with the games updated graphics.
Online play is truly the bread and butter of this experience. Yes, you still have arcade perfect arcade mode, and there is still a practice mode to hone your skills both of which are playable with any combination of graphics, sound and gameplay, but without online mode, this game wouldn't be as worth it as it is. The net code is the best there is in any fighting game to date, so the only thing you have to blame a loss on is your own playing. You can still chose to play in classic or HD Remix mode with classic or HD Remix graphics and soundtracks online, and you can join a friendly room of up to 6 total players with a smooth spectator mode. It's always easy to find a room, and the competition is always fierce.
With all the updates and the great online play, this is a no brainer for Street Fighter fans, and for those of you who really want to know what the big deal about Street Fighter really is and SFIV didn't convince you, I suggest you give Super Street Fighter II HD Remix a try.