My favorite TTRPG is also the only one I've played in years: GURPS. Yes, I am unhinged, yes, I've pirated everything, and yes, I use so many houserules that on several occasions my group have wondered what constitutes "still being GURPS". The next game I plan to run is inspired by Dynasty Warriors and Crusader Kings 3, and will be played in Tabletop Simulator due to the boardgame-like nature of my intended mass combat mode. Is this still GURPS? We may never know.

Sadly for wargames I can't get my group to stop playing Warhammer even though almost nobody seems to actually enjoy the games (one player in our crusade has lost every game they've ever played, usually by being tabled). I'd say Grimdark Future by OPR but I only ever managed to convince one person to play the game once and everyone else doesn't want to have to "learn a whole new system".