I tend to run through Tomb Raider (1996) and Tomb Raider II once a year. Tomb Raider III every few years.

Loads of Nintendo games are good to replay. I find it easy to pick up the likes of Yoshi's Island, Super Mario Bros 3, Super Mario World, Super Mario 64 or Super Mario Sunshine and run through them 100% in a number of days (or hours). Some of the 3D Zeldas, like Ocarina of Time, Wind Waker and Twilight Princess, I'll run through every three years or so. The Donkey Kong Country trilogy is also a joy to revisit.

Exhumed on the PS1 is great fun, I give that a play every now and then. The early Resident Evil and Dino Crisis titles also have a lot of replayability for me.

My whole life I've been replaying RPGs.
Ive played Chrono Trigger more times than I can keep track. Just last week I finished yet again. Its a fantastic game to go back to.
Ogre Battle 64, Suikoden II and Final Fantasy 12 are other games I keep coming back to whenever possible.
More recent ones would be Skyrim and Ni No Kuni 1.

Outside that genre, I'd say Uncharted 2, Horizon and Bloodborne. Even after I've platinumed them I just feel the need to go back to them.

The Baldur's Gate games, Betrayal at Krondor, Skyrim, Half-Life 2 with episodes. But the most fun is usually games that don't really end or have traditional or conventional playthroughs, such as the Civilization series or Mount & Blade (currently enjoying the hell out of the early access of Bannerlord as well).

Super Mario 64 (since I never beat the game)

Halo 4, Hellblade, Dead Space 2, and when I’m feeling nostalgic I bust out the GameCube and play RE 4, Metroid Prime, FZero GX.

All of them.

I don't mind replaying games I played through, even linear ones. And I rarely play multiplayer anyway.

Majora's Mask (3DS version), Ocarina of Time (same), Resident Evil 4 and Remake. God of War on PSP. Currently replaying Super Mario 64 DS which is vastly superior to the N64 version in my opinion. Super Mario Sunshine, although I haven't played it in a while as my Wii isn't connected to my TV anymore. Sonic 1, but I'll probably replay Sonic Mania instead in the future. Bioshock comes to mind as well.

Sorry for the boring answer
Rarely play the same game again
However, I remember that RE4 and RE5 were completed twice.

The amount of time I've spent going back and playing SNES games I've owned since I was a kid like Donkey Kong Country is crazy. A lot of games from back then are so good for just picking up and going through a dozen levels or so just for fun. There's not that barrier of commitment that newer games tend to have where you often can't just go back and select a certain level or section to replay.

The most I've played a game like that where you have to play through the campaign as a whole is RE4, which I have beaten 13 times to date.

If I were to take a game to a deserted island and play it for 6 months, it would be Metal Gear Solid: Peace Walker. After I complete the story, I tend to keep grinding the weapons, items and the rest of the content until I repeat the story yet again. I never get tired of it.