I picked up some Melee casually with friends last year, and now netplay is really good so I've kept playing with other friends.

I personally can't stand playing ultimate though. Something about the way the movement is defined doesn't jive with my expectation of how movement ought to work, so I just get shmoved on all the time. Not to mention that the online for Ultimate for me is unplayably laggy, so I don't keep it installed anymore.

Melee though is just cool. My friends and I describe it as having a basic set of axioms, and as long as the movement you try to do doesn't break the physics engine, it'll let you do it. The more modern games on the other hand are more of a state machine; all of the things that you can do are pretty much predefined by the developers. What this means is that there isn't an infinite skill ceiling in the same way. But even beyond that, I really enjoy the way movement in Melee feels. The controls are difficult, but they're very tight, and when you start executing better, the cool factor for what you can do to an opponent goes up. That's something that I think Ultimate failed to capture, I think in part because of Sakurai's insistence that Smash be treated as a casual party game only, and goes out of his way to try and neuter what makes the game viable as a competitive fighter.