OK, I don't like fighting games to any appreciable degree. Guilty Gear was OK and I loved Marvel v Capcom, but the rest tends to be blah. Virtua Fighter is way outside of my wheel house and I've always thought I'd enjoy Mortal Kombat and I am always disappointed. Dead or Alive is just a bit embarrassing to play. And I did NOT like SF 2, played a little bit of 3, but did like Alpha a lot.
SF IV is the newest entry into this series and, actually, it is kick-ass. A stunningly great fighter. It looks phenomenal. The animation is smooth as silk and the visuals are stylish and, well, a bit awesome. I cannot really fathom how anybody can really not enjoy the game.
The character list is deep, but not so overwhelmingly large that the characters become non-entities. All of them control well. But, there is a problem.
Mainly, Zangief is absurdly overpowered. He is laughably unbalanced. His spinning lariat is near untouchable. It can also be unleashed with a single button push on the default settings. It is comically easy to get perfect rounds on higher difficulties with him. It is nearly impossible to defeat him and it's going to be a bit of a challenge for you to lose with him. It also makes fighting anybody with him online the height of cheapness.
They follow that up with the AI-controlled Seth (when you control Seth, things change just a wee bit), the final boss. He is the single cheapest character I've ever seen. He can unleash combos that drop 1/3 of your health in seconds. He has a special attack that will suck you in from about half-way across the screen and allows him to slaughter you. He will make you throw controllers, he is so cheap.
Take away those problems and the game is top of the line. As it is, it simply must settle for being terrific.