Probably not "the strongest game visually" but one that had a big impact on me, Viewtiful Joe. This game engaged me from the first time I saw it, its distinctive but familiar look would be great as a cartoon, its just a shame that the average game is so far removed from 2d platformers at this stage that the game didnt sell as well as it should have.
Oh and Freespace 2 from way back, its the only spaceship game I have ever played that didnt feel empty. Even comparing it to recent title’s like X3 that use many of the same features this game just has more personality. Visually I think this game was very well directed and managed quite a few great cinematic moments.