A game which is as good as it's title is long...
This is essentially another version of a game which is over 20 years old. Now you might be thinking at this point - why on earth have Capcom resurrected this? Surely there's been some improvement in the fighting genre over the past two decades!?
Well, no, not definately. The fact is there is only a limited amount of complexity you want in a fighting game, and possibly only a certain 'type' of complexity too. The main competitor for Street Fighter 2 'back in the day' was Mortal Kombat and it's sequels. Mortal kombat was a very different games, very reliant on specials and not particularly balanced characters - there were characters who were significantly easier to win with. There were lots of moves and finishing moves to remember, and part of the entertainment was inputting a finishing move and watching the gore fly... A bit like entering a code rather than playing the game.
Streetfighter was a purer experience. Originally the characters weren't perfectly balanced, there were difficult matchups and most characters only had two or three at most specials. However, the range, priority and hitbox variation made the game very, very deep. Much deeper than it appeared to be on your first few plays. Simple to play, difficult to master, with a learning curve that meant you could potentially continue to improve almost indefinately.
What the developers have done with HD remix is take probably the best title in the Streetfighter 2 series and given it a 21st century overhaul. The new character and background graphics look great, the sound and music feels contemporary and an expert player has subtly tweaked the characters moves for a little more balance.
Games like Super Street Fighter 2 Turbo HD Remix are far better with a human opponent, and with XBOX live, you can always find one. Really, the online play feature and ranked modes are almost reason enough to re-introduce this game.
With all the improvements to graphics and sound and the re-balancing of characters, it is as good a game as you can want for 1 vs 1 2D fighting. Street Fighter 4 may have flashier 3D graphics and some interesting characters, but it still doesn't have the purity of Super Street Fighter 2 Turbo HD Remix.
It's not perfect, some glitches to scoring, lag issues and the rankings getting messed up near the start put a damper on this. There are still minor issues in here - Akuma is probably still very unbalanced if played as well as it's possible to play him... But it's still a great game.