I liked FFXII infinitely more than FFX. Tidus is just plain annoying, and XII's combat is the most engaging and fun battle system I've ever tried. The story is also better than X, in my opinion; it just is more global/political than character-focused. Plus, some of X's plot twists were just plain dumb.
Past that, you should definitely try out (in order of how much I like them):
-Mass Effect
-Any Shin Megami Tensei game. Like seriously, they're all amazing. On PS2: Digital Devil Saga 1 and 2, Devil Summoner 1 and 2, Nocturne, Persona 3 FES, Persona 4
-Fallout 3 and Oblivion, as have been suggested, though they're honestly more addicting than they are good games.
-Dragon Quest series, Rogue Galaxy, Dark Cloud series
-Any other FF game
-Suikoden series, Skies of Arcadia
-If you have a PS3: Valkyria Chronicles, Demon's Souls
-IF you have a DS: Chrono Trigger, Final Fantasy IV, The World Ends With You, the Mario and Luigi series
-Paper Mario series
-Knights of the Old Republic I and II.
There are a TON more, but that should probably do for now. Enjoy!
EDIT: Even though you're looking for something Gen 7, last generation really isn't that much of a downgrade, particularly since you love FFX, a last-generation game.
EDIT 2: Also, I have to say, Lost Odyssey (Xbox 360) is probably the most FFX-like game I've played other than FFX itself. It's turn-based and features current-generation graphics, along with a very engaging storyline. You'd enjoy it.