I fail to see why having sex appeal in a game nessecitates all this discussion and qualifiers.
The thing is that while there is a lot of eye candy, the series has lasted this long because it is actually a very good fighter, one of the best out there IMO.
While it got more outrageous over time, I will say that one of the things that carried it for me in the beginning was that they tried to make it sort of "realistic", one of the initial ways of hyping it was that it was a game that wasn't going to feature "dudes in Gis with the freak power to throw fireballs". It still looks very little like real fighting, especially in terms of the grapples and the lack of any kind of "ground game" (where a couple of serious fighters are going to wind up a lot of the time), but it was kind of neat for everyone to be a regular martial artist and have everything resolved with kung-fu rather than the use of super powers. Of course nowadays we have goverment conspiritices, cybernetic energy beings, demonic tengu with air control powers, and ninjas who teleport around and stuff... but it still has it's own unique style.
As far as characters go, it depends on the edition but Lei Fang, Ein (Hayate before he was outed/memory restored) and Hitomi are some of my favorite fighting game characters. I always thought that Ryu, Kasumi, and Ayane were a bit on the cheap side though, they get too much favortism due to the Ninja thing and tie in with the Ninja Gaiden franchise.
That said, I have Street Fighter IV as my only 3ds game for my 3ds right now, I think it's only 'ok' so I'm going to probably hold off on an initial purchuse here until I find out more about how the game holds up. See, I'm old enough to buy/watch porn if I want it, and while the eye candy certainly doesn't hurt the game, it's kind of pointless to get a game I'm not going to have some fun actually playing. So far I have yet to find a portable fighting game that has really blown me away, and I've gotten a ton of them over the years, I can't think of any that were above the 'ok' level and moved up to 'very good' or 'excellent'.
