Well this thread sure got big fast.
3rd Strike will probably go unbeaten for best looking in-game 2D animation.
It has incredibly smooth animation, that's for certain, but any game that uses the technique of panning the segments of multi-segmented sprites technically has even smoother animation (as they don't skip any space when they move). And the actual character designs look like shit. I've never considered 3rd Strike to be a very good looking game, no matter how smooth the animation is.
Anyhow, here are my picks:
Super Mario Bros. is hands down the most memorable looking game of all time. Anyone who was a kid in the 1980's should be able to visualize the entirety of stage 1-1 from that game at will.
Super Mario Bros. 3 and
Super Mario World are two more games that I think most of us will remember for a long time to come. Who could forget Racoon Mario, Yoshi, etc.?
Duck Hunt. There's probably no other game where every single screen is so memorable (even if there are only two of them).
Tetris. Without a doubt the most easily recognizable game ever made.
Pac-Man, Pong, and Donkey Kong all deserve a mention, as they are almost inarguably among the most memorable looking games ever made.
Final Fight has some of the most memorable character designs ever.
Street Fighter II deserves a mention for the same reason.
Joy Mecha Fight has some of my favorite character designs.
Samurai Shodown 1 & 2 are probably the best looking of SNK's early titles, and
the Metal Slug series would rank as their best looking series overall, but I'd still rank
King of Fighters '99 as their best looking game.
Every Fire Pro after and including Special. Forget 3rd Strike.
These are the best animated games ever made.
Every Parodius. Probably the best looking series ever overall.
Pu-Li-Ru-La has to be seen to be believed.
When I first heard about
King of Fighters XII I expected that it would look like shit. Needless to say, I was pleasently surprised.
The original SFC version of
Tales of Phantasia is probably my favorite looking RPG ever. Everything from the sprite are itself to the movement effects is just incredible.
I don't think any game has ever used its visuals to tell a story better than the remake of
Famicom Tantei Club Part II for SFC. If there's any contender for this title then it would have to be the original
Clock Tower for SFC.
Rob's article on HG101 completely sold me on all things relating to
the Splatterhouse series. What a fantastic looking bunch of games those are.
Am I the only one who thinks that the original
Castlevania is still the best looking game in the series?
The only other game that comes to mind immediately is
Majyuuou, but I'm sure there are craploads of other games that I'm forgetting.