For long term campaigns as a DM that would be BECMI D&D (later Rules Cyclopedia D&D for the pedants who insist that they're different), Marvel Superheroes, Torg (original flavor), D&D 3e, D&D 4e, D&D 5e, and 13th Age. As a player AD&D 1e, 2e, Ars Magica and Mage the Ascension. (I played and DMed a lot more in the 90s when I was in High School/college than I manage these days).
Very few non-D&D games in there, but I think that's because D&D has levels and so everyone thinks you're supposed to run a long campaign with it and expectations of that are baked in. Most of the non-D&D, non-13A games I run/play these days are either one-shots, "long one-shots" designed to run around 4-5 sessions at most as a change of pace, or "linked one-shots" of some game when we're down a person for our regular 13th Age game (Torg Eternity has become the game of choice on that front in the past year).