Real Racing, Zen Bound 2, and maybe Nova or Archetype (they're all great on retina display at least). As far as use of graphics goes, which I think is more important, Spider, Zen Bound 2 again, Canabalt, and certain other retroish games (maybe HookChamp) get my vote.
Thanks to everyone who mentioned our baby The discussions around this topic tend to fall apart because hardly ever any common criteria are established. Game graphics can be picked apart and analyzed in many ways, and outside of pure subjective arguments, visuals can (and should!) be awarded both by their technical and artistic merits. Technical issues are easy to spot, telltale signs are blurry or blocky textures, choppy frame-rates, flickering, poorly thought-out menus and UI, etc. And for "best" graphics any of the above are inexcusable. As far as artistic merits go, tastes vary, but in general good visual design requires well-selected color palettes and fonts, clean layouts, appealing character design, a good understanding of lighting and composition etc. A huge factor is also how well the graphics serve the usability and gameplay on the target device. When you examine the majority of the popular iPhone games under these criteria, only few titles score top marks and even fewer developers do so consistently. If I had to pick one developer as the benchmark, it would be Illusion Labs.
It's like you take Dungeon Hunter, make a better story, give it a soul, and finally add something I like to call 'fun'.
Lol. Yeah. The graphics in Labyrinth 2 and Zen Bound 2 both make my jaw drop, but the graphics in Zen Bound 2 make my jaw drop a little more. And it's a great game. I already own Zen Bound 2, and I'm currently TRYING to make myself get Labyrinth 2. Totally agree. I love how the developer was able to simulate global illumination (colors reflecting off each other). That must have taken some very careful and tricky texture mapping.