Replayability is pretty much what separates great games from the very best games for me. There are a lot of games that I would give 90-99 scores to, but the ones that I can replay and still enjoy and capture what I loved in the first place are the true 100s for me. And for me, those are Ocarina of Time, Xenoblade Chronicles, Fire Emblem: Awakening, and quite possibly Breath of the Wild. Though there are other games that I wouldn't say are perfect that I've really enjoyed replaying, like the first two Paper Mario games, the original Pokemon games, Kid Icarus: Uprising, Twilight Princess, Skyward Sword, A Link Between Worlds. Obviously I don't think online/multiplayer focused games like Splatoon and such really count for this type of thing, though I've put 400+ hours into that game and can't wait for Splatoon 2!
Upcoming Games To Get
Definite: Kirby Star Allies (Switch), Mario Tennis Aces (Switch), Fire Emblem (Switch), Yoshi (Switch), Pokemon (Switch), Kingdom Hearts 3 (PS4), Monster Hunter World (PS4)
Considering: Fe (Switch), Donkey Kong Country Tropical Freeze (Switch), The World Ends With You (Switch), Ys VIII (Switch), Street Fighter V: Arcade Edition (PS4), Kingdom Hearts 2.8 Remix (PS4), The Last Guardian (PS4), Shadow of the Colossus HD (PS4), Anthem (PS4), Shenmue 3 (PS4), WiLD (PS4)