Games with visual/audio design that rocks my socks off. There's definitely a lot more I could put on here but as far as a solid combination of both worlds, this is what I have in mind.

I'm very partial to wireframes, unique shaders, exceptional lighting effects. UI also plays a big part with either minimalist or just incredibly ornate styles, or even having information presented in interesting ways. With audio, I just like a banger soundtrack and just really detailed sound effects or stuff that's just a little off beat.