I already have SSF4... should I rebuy it on the 3ds?

Topic really says it all. I'll probably get Nintendogs+cats for sure, but I'm unsure if I want to buy ssf4 because I already have it on ps3 and iphone. Not sure if I want to pay 3x for the same game. Should I still get it or a different game? Ridge Racer and Pilotwings seems nice.

Depends on how much you like the game. I have the game and I can tell you graphically it is very similar to the console versions considering screen size, the animations are all great, the controls are still tight, and it feels like the same game with some extras which are nicely included. I would say it is up to you, although Ridge Racer seems to be a hit but the only positive thing I have heard is that the 3D occurs with great ease.

Both good points. I do like Street fighter, but am not a hardcore fan or anything. That just might leave Pilotwings and Ridge Racer... hmmm....

Well if you are not a hardcore fan then I would recommend Ridge Racer, I wouldn't recommend Pilotwings since I have been told the amount of playtime overall is quite small for a £30 or $40 game, it was something of up to 10 hours max i think.