I am currently playing back through Deus Ex: Mankind Divided. I love finding things I haven't found before and playing different ways. Alien Isolation is another replay favourite of mine, I love to find detail on architecture in hard to find corners, shows great attention to detail. Also, obviously, GTA 5. Which games do you like to return to?
Unreal world. Must have been playing it for 15+ years, dropping in and out to see how its being developed.
Crysis (though haven't replayed it for a while) Mass Effect 2+3 (haven't bought the remaster yet) Gears of War 5 (co-op)
Sensible world of soccer, theres joys to be had buying unknown players and ranking them up to players with million pund price tags. why oh why did jon hare want to try 3d with i'll never know the series should still be going strong also add conon fodder and syndicate/syndicate wars to my most played games
Both of which are currently free on GoG https://www.gog.com/promo/rerelease_ultima_underworld_and_syndicate
I quite like doing replays of Vampires the Masquerade: Bloodlines, Metal Gear Solid V: Phantom Pain is another that I like doing different play throughs with to see if I missed anything on any of the levels. I also play X4 Foundations and No Man's Sky a lot with fresh starts, lots of hidden bits of lore and new things to discover in both of those.
Not really a top-drawer title like some of these classics, but I play Call of Juarez: Gunslinger quite a bit, entertaining fun for a few hours when you need something to fill a non-serious void.
State of Decay 2, I have probably 2500 hours in it. I play it now on hardest difficulty with no hud and lots of extra self imposed handicaps to make it a challenge. Lots of modding support on PC and the devs are still supporting it with good updates. Well worth the price of entry.
Xcom Enemy Unknown / Enemy Within So easy to drop in an do a couple battles. Save whenever you like. A game that doesn't need time, but it might end up demanding it heh. Mass Effect Trilogy. Sci Fi perfection. Dragon Age franchise. High fantasy fun. Worms Yeah, even now. Other than Cannon Fodder, what else can even compare? Deus Ex All the games have so much fun factor to go back for. Stealth, Tech, or balls to the wall carnage. Final Fantasy 6 - 10 Most of my hours were on console, but these games have something that tugs me back. Fallout / Elder Scrolls All of them pretty much. Open world, new builds, a reason to go from A to B while getting ALL the powas. More besides, **** I get more joy from replaying games than I do from the new ones. Like how many times I played Monkey Island over the years?!
Ive play Mafia The Definitive Edition a couple times through .. was going to do a third. Looks gorgeous on my C9 OLED at 4k and the story line is just brilliant. Oh and lets not forget Wow classic .. levelling in the Barrens with the music on is just pure pleasure.
Sniper Elite 4 for me, constantly trying to find different angles for shots. i even had one complete run through i titled scrotal destruction. with the DLC over 1000 testicle shots
Games I play that have real replay value are sports sim games. I play Digital Diamond Baseball, Action! PC Baseball, Strat-O-Matic Baseball, PC Replay Baseball, and more. You can replay every season in MLB ever with many options including with as played lineups. There are actually other sports sim games I have for hockey, basketball, golf and football that let me do the same thing but those sports don't grab me the same way. As for other games with replay value there are some I have played that I would definitely play again now but it requires others I know wanting to play them. I'd rather not play online against strangers playing converted board games and such.