Uhhhh Final Fantasy 13 series ;)

I'd be careful about recommending the Two Worlds games, they've got the design mentality but also a crapload of flaws and technical issues.

For my own list of recommendations... well, there aren't many games that get Ultima 7's balanced blend of roleplay, world-exploration, and story! The Elder Scrolls in general comes pretty close, but keep in mind it's first-person action combat (though it also has a third-person-camera option, this doesn't change the mechanics of how things function at all), and Fallout 3 and New Vegas are in the same mold, just in a different setting.

Baldur's Gate 1 has a very open-world feel to it, even though the world is broken up into square chunks.

Kingdoms of Amalur: Reckoning has a pretty open world and an MMO-like assortment of sidequests but it's not as great RP-wise and the story itself is pretty dang dry and standard on the whole. It's a good action-RPG fix for people who enjoyed Fable II, though, with some elements of Elder Scrolls and similar games thrown in (crafting and ingredient-gathering and such).

Dragon's Dogma: Dark Arisen on consoles is a pretty decent choice. It has a solid combat system and a lot of content and exploration value.

The Witcher games are also pretty great, yeah, but keep in mind your enjoyment of the RP aspects will hinge entirely on your ability to like Geralt (pro tip: consider switching the game to Polish so he can have an actually decent-sounding voice actor--that's the game's native language anyway).

The only game slightly similar in world exploration and atmosphere to Ultima VII is Baldur's Gate 1 for me: It's relatively open - although the world is separated in many maps, all the parts fit together as one big world. Compared to BG2, where you are merely "sightseeing" the world's most interesting parts, in BG1 you explore "real" nature and wilderness, sometimes finding caves with secrets, lost places and lonely characters. It's the only game I have a similar feeling like in Ultima VII, as you travel with a party and have a similar view of the game.

Another game with a very similar feeling is Gothic 2 for me: Here you have an open 3D-world to explore, full of hidden places, caves, plants to pick up - but with no party to go with. However, Gothic 2 is the only game I know that manages to make the game world in a comparable way "living" like UVII does: Every single NPC has his schedule, you can interact with many little things in the gameworld and the world reacts directly on your actions like in Ultima VII. The world is full of the same details that make Ultima VII so immersive.

If you are more on the lighter side of gaming, Driftmoon could be an alternative: It's a direct hommage to Ultima VII, with many of the details of the game, but relatively simple and not open world. There are many little things and easter eggs to discover however.
For the Divinity-games I never had a nerve, and especially the newest part didn't thrill me - Divinity tries to do many things Ultima VII did, but the developers forgot something as important for immersion like schedules and day/night-cycles. For me it's exactly these aspects that make Ultima VII great.

So, to resume: Ultima VII, BG1 and Gothic 2 are my personal favourites, as I love rewarding exploration, immersive and believable gameworlds (with day/night-cycles, schedules and direct reactions to my actions) and the feeling of real adventure.