The Elder Scrolls series seems like it'd be up your ally; huge open-world RPGs with plenty of interesting quests, characters and dungeons to explore. My favourite by far is Oblivion. It's kept me busy for hundreds of hours over the last few years and even now I like to go back to it every once in awhile. Get the Shivering Isles DLC with it as well. Shivering Isles adds a great amount of content with a whole new flavour to it and is really just an all-around excellent addition to the game, especially after you're done with all the main and guild quests and find yourself wanting more. Some people like Skyrim...I'm not one of those people, so I'm not going to recommend it, though it might tickle your fancy more than Oblivion, depending on your tastes. Morrowind is also great, but it shows its age and mods are pretty much required to gain much enjoyment from the experience these days, in my humble opinion, unless you have a great deal of patience.
I love JRPGs, so naturally I'm going to give another recommendation for Persona 3 and 4,
especially 3. I'm in the minority with that opinion, but while I really enjoyed my time with P4G, Persona 3 is my one true love. I liked the characters, story, setting and overall vibe of the game a lot better. Both are grindy games, but it never felt like a chore to me in P3. Either way, if you have any interest at all in playing both eventually, it would be wisest to start with Persona 3, as it could feel like a step backwards gameplay-wise after the improvements Persona 4 made and could make it harder to enjoy for what it is.
It sounds like you haven't played any Final Fantasy games yet either. The Final Fantasy series is among my favourites overall, so I would encourage you to give a few of them a try. They're all quite different from each other, so it really depends on what you want most from a game, but it seems like you really enjoy a good narrative, so I'm going to give my recommendation for VI and X (though I'd probably recommend them regardless, since they're my two favourites, with VII following a few steps behind
). VI was originally a SNES game (there are also PS1, GameBoy Advance and even iOS versions available, though the iOS remake took away a lot of its visual charm with the new character models), so it's pretty "retro," but I only played it about a year ago and found that the 16-bit graphics are still beautiful even to this day. The characters and story are very compelling and the battle system, while simplistic, is satisfying. If you're open to older JRPGs, chances are you'll love VI.
Final Fantasy X is more modern. As an early PS2 game, it's also been remastered recently for the PS3 and Vita and it looks simply gorgeous with new coat of HD paint. While more linear than previous Final Fantasy games, it also places the heaviest emphasis on its story and you really feel like you're on a journey with the characters. Its battle system is also a little different from its predecessors; the active-time battle system came about in Final Fantasy III (I think) and had been implemented in the main series ever since, up until X, which went back to a fully turn-based system. But my god, it's such a beautifully crafted, intricate, strategic piece of work. I can't really say whether it's better or worse than the ATB system, but going back to X a little while ago after playing a lot of the older Final Fantasies, I really appreciated the change.
Even just one decent RPG should be enough to keep you busy for quite some time, but I'm going to recommend just a few more games, just because they're awesome and you'll probably enjoy them: BioShock, The Walking Dead and Sly 2: Band of Thieves. BioShock, while first and foremost a FPS, also has some RPG elements that I found to be rather fun. I don't normally like playing straight-up first-person shooters, but BioShock brought enough to the table to make the gameplay interesting for me, not to mention the setting of Rapture and the game's storyline is reason alone for a lot of people. If you decide to try it and really enjoy the gameplay like I did, BioShock 2 is worth checking out, as well as its DLC Minerva's Den. As for Infinite...see my earlier comments on Skyrim, basically. Plenty of people like it, but it lacked the major reason I liked the original BioShock so much in the first place. Now The Walking Dead has a fantastic narrative, though be warned that it's a little light on traditional gameplay. What you'll mostly be doing in the game is interacting with the other characters, QTEs (don't be scared though, I normally hate QTEs but thought TWD handled them really well) and solving some puzzles. It's really all about you and the story though. And lastly, I don't know if you're into platformers, but Sly 2: Band of Thieves is one of my all-time favourite games. In fact it's one of the main reasons I got so into video games. It was originally a PS2 title but has also gotten the HD treatment, along with Sly 1 and 3, for the PS3. You can download it on its own or get the whole collection. Either way you wouldn't go wrong; they're all pretty fun games in their own ways.
Anyway, I hope you find something you like. In general my advice to you when it comes to getting out of a gaming rut would simply be to have an open mind. There are so many different kinds of games out there with so much to explore. If you have a chance to try something, even if you don't think you'll like it, it's usually worth a fair shot. Sometimes you'll be surprised.