A constantly ongoing project
The Simpsons soundboard is a very complex project...you could probably find up to at least 20 good quotes from various characters in just one single episode. That's why I give you props for at least staring a soundboard. If you really get into it, you should just not re-submit for a long time, or you could make V1.51, 1.52, etc. You just need a balance of clips for each character. Like, Marge only has one clip (not to mention that she's listed under "townspeople" and not on the main page), and Homer has like 20.
I would say that Home is a funnier character and has more to say, but the key to having a great soundboard, no matter its size, is to balance out your quotes. Your sound quality has not reached Family Guy 3 soundboard, but it doesn't sound too bad from here.
I would say to spruce your graphics a little bit, but its hard to have those images all compressed down on the screen. So here's my advice: take a large picture of a character, and cut the head away, and just use that for each. It would a lot better, and would make better icons that don't look so stretched.
But, those are just minute details. Do what you like.
I've also written reviews for two Family Guy soundboards (I think), and maybe the original Simpsons one. Keep up the good work, your stuff is improving!