I meant among CONSOLE games (yea, Counterstrike is the biggest, then probably World of Warcraft or Battlefield or something else).
Oh yea, i wanted to mention that I think Quill makes some awesome logical points. I actually prefer Street Fighter 2-style fighters, but I can't deny that SSBM is a legitate fighter (with it's own unquie style).
I have to say that I haven't played any fighters on the last 2 generation-systems with the exception of Melee (for about 4 hours) and DOA4 (for about 10 minutes). SFII Turbo (SNES) will probably always be my favorite, but SSB is really fun, and can be deep if you want it to be.
I think one of the biggest differences is the computer opponents. In Street Fighter, they're very methodical and usually (or supposed) to get progressively harder--although Sagat was always the most irritating to me. In SSB, the opponents are a bit more spastic, which is predictable (imagine if SF2 was played on multiple ledges...), and I guess is why you have different challenges, like the Master Hand, big DK, 100 Yoshis, etc..
Playing solo, I'd opt for Street Fighter 2...which in the day, I was by myself most of the time. But if I had another human (being my younger brother), we always chose SSB and because his skill level was equal to mine, you HAD to use some tactics to keep up. It's SUPPOSED to be multiplayer, whereas SFII can be very challenging and engaging with one player.
From experience, SSB can be just as chess-like as any other fighter, though you need a worthy opponent.