A site where you can get CGNMario's creations (also known as N-Mario).
The site where you can get the latest version of MUGEN.
You can get Phantom.of.the.Server's creations here. He's got some good stuff. My favorite char, Rare Akuma, is also here.
The largest MUGEN forum in the world. They have a lot of good chars you can download here.
A site where you can get fhqwhgads7's MUGEN creations. I host my H-Loader portraits for his Giygas.
MUGEN website made by my friend GBA64.