I've experience with D&D 2nd-5th edition (yes, even 4th, though in a far more limited capacity and I've forgotten everything since then), Pathfinder 1e and 2e, Savage Worlds, and a smattering of other RPG's. However it's those other RPG's I'm interested in playing now! City of Mist, Spire and Heart, Broken Tales, damn near any Free League game, Mothership, and to some extent Shadowdark and the Mork Borg compatible games (but I'm itching to move away from the more D&D-like RPG's).
I'll be the first to admit, Roll20 is my least favorite VTT of the four I make use of, however it's the one I have probably the second most experience with, and it's currently the most popular and most accessible. So I'll endure the ugly UI in favor of partaking in the wonderful world of RPG's!
Please note: Nothing against the people who own and operate it, and despite my dislike of the UI, it was the first VTT I used that properly incorporated music, and that alone has been worth my superficial picking of nits.
Anyway, despite that, I do like using Roll20 when other VTT's don't support what I want to play. I enjoy Fantasy Grounds, but it loses all luster when you're trying to run something that doesn't have module support. AlchemyRPG is wonderfully atmospheric, but their system builder takes work and maybe I want to play something NOW. So here comes Roll20 with for the win.
Anyway, that's enough rambling, on with the games!
P.S. A good number of games in my 'enjoys playing' list are games I have, but have little to no experience running, planning on changing that soon!