If we're talking current gen, I think Sunset Overdrive performs better than most think. Never a dropped frame, and ridiculous draw distance (although shimmer on those far off edges, but I guess you don't look into the distance often). Forza Horizon 2 is even more impressive with the hundreds of far off and close dynamic lights casting on the car and the permanent headlight shadow cast.
Moving backwards, I was actually surprised Skyrim ran so well on 360 for its time. It was definitely begging for better hardware but it held up admirably.
A special mention goes to Halo 2 on Xbox, which pushed its hardware but simply couldn't quite achieve its look in most places except for a few skyboxes. The new lighting and textures in H2A really show what Bungie was trying to highlight but couldn't with reused assets and a crummy resolution.
Ridge Racer's unrelenting 60fps and relatively advanced simulation on PS1 is probably as far back as I can go for technical prowess.
Again on PS1, Tony Hawk (can't remember which one, all I remember is I started from scratch every time because I had no save card), showed technical scope and surprisingly good artwork for such a godawfully weak system. That game really did define a generation for me.
