I would highly recommend Street Fighter X Tekken as it is amazingly fun but you know that you still have to learn the complexities to get good whereas the last Street Fighter crossover, Marvel VS Capcom 3, was was too easy to do combos and it was too tempting for new players like me to just button mash away. I also think that the roster is better than Street Fighter 4, 'cause Jin and Cole are extremely fun and the joke characters are hilarious! I'm FAR from an expert on these things, but it's probably my favorite fighter yet (beating out SF4, Blazblue: Continuum Shift, Tekken 6, Marvel VS Capcom 2/3, and Street Fighter 2, though that one is better in a historically important sense).