Killzone 2, God of War III, God of War Ascension, Uncharted 3 and Grand Theft Auto V. No other game came close to these imo.
Overall I think most impressive was Uncharted 3. Not just because unlike GoW had a controllable camera, or because it looked a generation above Uncharted 2, but because it could legit be a PS5 release and still be able to impress.
*Gravel below is not a 2D texture, but the best use of bump mapping I've ever seen:
Especially in motion and in particular when crazy stuff happens like burning chateau, cruise ship level and exploding plane. It's simply unbeliavable.
Unlike previous two titles, PS4 "Remaster" simply bumped resolution from native 720p to 1080p and framerate to 60fps.
No texture changes (for obvious reasons) some textures where updated in resolution, but never altered in artwork and the most impressive ones are identical on PS3 even in resolution, some physics and lighting downgrades.
Apologies for the many shots, had to quickly chose from more than 400.