For me it was the original Sacred. Was the first game I really played in MP and where I met so many peeps I still talk with today like gogo and Schot. Was in the beta for Sacred 2 and think the allure faded for me before it was even actually released. Oh I still immensely enjoyed it but the first one was such a new experience for me and meeting all the great people in HC really left it's indelible mark on me.
Delta, I'm on Stream but these days I seem be playing mostly SP games ( like Rimworld, They Are Billions, Crashlands etc). I just have such limited time to play that coordinating game times would be arduous for me. Also I have a hard time with FPS type games. Action is too fast for me now (getting old ) and fast movements tend to blur my vision. That said I do play a lot of Grim Dawn. They do have MP though it's more of an add-on than a core part of game. If you're interested in it, especially for MP, I would talk with Dorimil. He has played quite a bit of MP and could tell you what to expect.
My Steam name is Knuckles (weird huh) but I guess there are a couple of us....so look for the one with 'Robb' in the profile.
Actually I'll just send you an invite