Wind Waker HD, Mario Kart 8, Xenoblade Chronicles, Skyward Sword, Ocarina of Time 3D, and I've personally been impressed lately with Captain Toad: Treasure Tracker...it's a step above Mario 3D World in textures and especially lighting.
Looking ahead, I find Yoshi's Woolly World and The Legend of Zelda U to be quite stunning so far. Xenoblade Chronicles X looks great as well...especially the draw distance and the overall scope/scale, but I wish they were using a bit brighter colors like the original Xenoblade Chronicles.
Upcoming Games To Get
Definite: Kirby Star Allies (Switch), Mario Tennis Aces (Switch), Fire Emblem (Switch), Yoshi (Switch), Pokemon (Switch), Kingdom Hearts 3 (PS4), Monster Hunter World (PS4)
Considering: Fe (Switch), Donkey Kong Country Tropical Freeze (Switch), The World Ends With You (Switch), Ys VIII (Switch), Street Fighter V: Arcade Edition (PS4), Kingdom Hearts 2.8 Remix (PS4), The Last Guardian (PS4), Shadow of the Colossus HD (PS4), Anthem (PS4), Shenmue 3 (PS4), WiLD (PS4)