After finishing Red Dead Redemption on Xenia, I have a weird itch to play some more of the open world games I've missed. I was just completely exhausted with sandbox games by around 2013 and avoided all of them, even the ones I heard good things about.
Some of the games on my "maybe check out" list:
Sleeping Dogs - Apparently a really good GTA clone. The Hong Kong setting and melee combat make it stand out.
Assassin's Creed 4 - The two additional Ezio games and Assassin's Creed 3 were big factors in why I got completely burned out on open world games but the ship combat is supposed to be really good- also pirates are cool. It should also predate the series turning into a singleplayer MMO thing.
Far Cry 3 - Never got around to playing this despite all the praise. I know the FC3 style got milked to death but there's probably a reason it became used as a template for Ubisoft games. Wasn't this also the game with the retrofuturistic 1980s DLC campaign with Michael Biehn?
Mad Max - From what I've seen this is a pretty generic open world game in the vein of the later Arkham games but it seemed like a pretty faithful recreation of the Mad Max world in video game form.
I have no idea what 7 and 8 gen mean (I'm not a very good gamer), however, I'm going to take this opportunity to shill for Pathologic 2, because it is (technically, ok, more than technically, it is, it's just a weird example of) an open world game, and it's amazing. It's not the power fantasy most open world games are, you'll never really feel like you're "winning", but it's an amazing, beautiful experience that I try to convince more people to play at just about every opportunity. Oh, also, it's not a sequel or anything. You don't have to (and, really, probably shouldn't) play Pathologic before playing Pathologic 2. It's more of a remake, but it's extremely stand alone and amazing. It's from like 2018, maybe? I'm not really sure and refuse to actually look it up.
7th gen: PS3, Xbox 360, Wii
8th gen: PS4, Xbox One, WiiU (not sure how the Switch fits in)