Yoshi's Island has got some of the most beautiful graphics on the SNES. The sunset, which can be seen in certain levels in the game (e.g. 3-1, 6-1), is one of the most beautiful ones especially for being layer 3 image.
Note that to fully use this background, you need both, a sprite status bar and UberASM. The former because it's a fullscreen background and the latter because of the (required) background gradient HDMA and parallax scroll.