https://www.pathofexile.com/

Been playing this a lot lately. It's a free to play Diablo clone. I'm enjoying it more than I ever enjoyed Diablo 3. The skill tree and player progression system is crazy, and the randomly generated maps in the endgame can be a lot of fun. Itemization is also better than D3, IMO. They seem pretty hardcore against pay-to-win, which is a big plus. The fanbase has been rabid enough that people are buying $1000 packages to build their own unique items, so they seem to be financially supported even without it. My only gripe is the group drop system, which is the Diablo 2 style free-for-all, and not the superior D3 individually generated drops - the one advantage that D3 has on them.

There seem to be a lot of good free to play games around.