I think that each generations have had their respective "bests" in terms of graphics and art style. For each four or five years of gaming (along with the hardware evolution) I've experienced since the early 1990's I could name a good 10+ "groundbreaking" titles which, at their respective time, were for all intent and purposes unequaled (for their time, and perhaps a few years to follow when we had those so called "ahead of their time" games).
Not all cases were only awesome for the graphics but also because they combined the talented work of the developers for all of the game's visual and audio elements, be it from the ambiance and atmosphere (both from the visuals and audio) to the game's soundtrack or the main character or the enemies' animations, or the clever use of the game's own features, controls, camera system and brilliant puzzle-solving or efficient platforming and good story-telling. It is rare when a game "with good graphics" can also be pointed at for much more than that alone, but it does happen from time to time.
It's of course very subjective, and it obviously depends on the games that the person has actually played, rather than just seeing footage or pictures of it (which often doesn't do justice to the games in question). For example I haven't played Metro 2033 nor BF3 and only saw some footage of them here and there simply because I never was interested much by them, so I can't really judge their graphical styles and presentation or complexity. I'd have to say that the last game I've played in which I was genuinely impressed by its art style, scale and vibrancy more than anything else is (as surprising as it may be to some) TERA, and to some extent I would also add Guild Wars 2 to this humble list. They're both impressive (mostly visually of course) in their own respective ways, where TERA is more fantasy-based and shows it marvelously well, is also very color-vibrant and diverse, whilst GW2 has more of that "photo-realism" visual vibe going for it, not to mention its scale as well and animations quality, all contribute to a pleasant visual experience.
But honestly, TERA has been the one out of those I've played since a few years in which I've stopped playing just so I could stare at some of the scenery (not all locations mind you, but some are really impressive). There's one place specifically which got my attention right away when I just happened to zoom the camera away from my character to look around. It's in the "Tempest Reach" map, which I think is in the Westonia zone (happens to be the name of one of the servers as well). There's a gigantic frozen lake there, with old-style pirate ships hanging on top of big frozen waves and twisted water shapes, as if the wind itself got frozen with the water. It's a bit difficult to describe (just go on Google Images and check for TERA Tempest Reach zone, or map, or something like that and you might see it) but simply beautiful to look at. There's also a very beautiful background (animated to some degree, with a beautiful waterfall) in the starting zone, and a superb, inspiring and calm lake called Seren's Lake which is amongst the best-looking place in the game (and some of the best looking lake I've seen in any fantasy-based games to this day).
And sure Guild Wars 2 also had impressive maps, some are very complex and I can't imagine the number of hours those map designers spent on making them (and drawing them too when they had to brainstorm everything prior to actually developing them). I mean those big (and some quite complex) locations like Lion's Arch, Divinity's Reach or the Black Citadel just to name a few (and many others). Not only are such places beautiful (architecture, culture being represented by them, or the colors and materials used to build seen by the textures, etc) but they fit and represent the game and its universe, both contextually within the game for actual game-play related purposes (such as being a "hub" for players, for its story telling, the quests) and for its universe so to speak. For example when I walk around in Lion's Arch I immediately "feel like this is Guild Wars' universe", rather than for example exploring "yet another cave somewhere" which itself looks like another cave in another fantasy game... know what I mean there guys? Some locations in some games really do distinguish their respective universes and sometimes even unique game-play related features (take the Citadel or Omega in the Mass Effect universe for example, or Denerim and the Deep Roads in Dragon Age, or what would Half-Life be without Sector-C Test Labs and the XEN world, or the original Crysis' alien no-gravity ship level, the same can be said again about TERA and some of its distinguished locations like most of Arcadia's, Velika, Allemantheia and many others, etc).
All of that and even more is part of the experience which is ultimately tied to, from and/or to the "graphics" (or rather "visual" experience I'd call it). To me it goes beyond "photo-realism" (when there's any of it, like in STALKER for example, in which case it was literally true, since the devs actually went to Chernobyl to take pictures to work with as part of the game's textures assets) or the number of polygons on buildings, characters, vehicles or weapons. I don't mind if it's "blocky" depending on what was the developers' intention (see Minecraft for instance) and even beyond the textures' quality (or resolution) to some degree. Now of course if for example Skyrim (or even Oblivion) had "better" (I.E higher res) textures from the start (rather than waiting for community-made textures to "fix" it) it would certainly "help" increase the immersion, but generally-speaking if it "fits" with the rest of the game, its universe, what it tries to tell us and make us feel like (via its story or its atmosphere, etc) then I call it "job done".
I do have my own disappointments of course, but I also understand that there's hardware limitations the devs have to work with (especially when it comes from a port of a generation of consoles that's about seven years-old by now, can't expect 2048x2048 res textures left and right in such cases huh?). If a game manages to capture my attention, however, to immerse me within its universe and make me care about the story and/or characters then more often than not I will at the very least "get used to" the low-quality graphics (if that's what I'd be thinking from the first impressions) and even like them overall after some time (this was the game for me with a couple of games recently like Diablo III, which I thought looked "too cartoonish" but over time I thought "this game actually looks amazing"... now of course the actual game-play is boring but visually-speaking I think it's top-notch and the attention to details they actually put in there is just exemplary, but feel free to disagree).
So... to simply answer the poll directly I went with "Other" since I'd really go with TERA without hesitation, and Guild Wars 2 very closely following it. I'd also give Mass Effect 2 a very honorable mention for being visually more "fitting" in the trilogy (in my opinion), especially with the inclusion of Omega which is just as visually poignant and representative of that universe as the Citadel was back in ME1 (as for ME3 there's unfortunately not much that distinguishes that one from the rest other than perhaps the remodeling/adjustments and facial texturing of some of the returning characters, the rest is pretty much "been there, done that, seen that" material).
I have to mention that I've seen a lot of footage of both Crysis 3 (which is starting to get interesting to me now, never got in Crysis 2 at all, tried it on my cousin's 360 and thought it was quite boring overall, couldn't be immersed at all but that's perhaps because it was a rent and I didn't get to play long enough) and Bioshock Infinite and I think that just by looking at said footage (HD that is, on YouTube mostly) and some pictures they definitely look very good on their own and in respect to their universes, story and contexts (of course especially Bioshock Infinite). I'll probably buy them eventually but for now I can't judge their visuals.