I had played Knights of the Old Republic but ME2 seemed like the evolution of that game—better characters, cinematic plot, really interesting gameplay.
I really enjoy the classic Bioware games (KOTOR, ~~Jade Empire~~¹, Mass Effect, Dragon Age: Origins, and Mass Effect 2) and I wish more studios took the Bioware formula, where you visit a few distinct semi-open locations with a bunch of interesting followers, and made games using it. I guess Spiders (Mars: War Logs, Technomancer, Greedfall) are kinda close, but their games are still missing something.
¹I haven't played it yet.