If anything the strongest pull is the online mode. They just pull it off so well. Your skill level is actually taken into consideration and they try to match you appropriately based on BP, Win/Loss Ratio, etc. For the most part it actually works too. Connections are solid too. I haven't played a laggy match yet.
Finally, and most importantly is the characters. Most fighting games have certain characters that are just over the top and unbeatable. Some would have you believe that's the case with Street Fighter 4. Well it's not. Every character is completely balanced. You can pretty much beat anyone with anyone. (While most would expect Gouken to be unstoppable I've beaten quite a few on my skill lvl with Sakura.) Basically you know that if you lost a match, then the other person was plain better than you. Simple as that.
So if you're looking for minigames or anything like that this isn't for you. But if you want a solid fighting game that takes everything it brings to the table and executes it damn near perfectly then SF4 is for you. ^_^