I'd love to see the N64 if possible, but most likely it's not since the Wii can barely handle it. A GB/GBC/GBA emulator would be great too.
The 3DS kicks the Wiis butt hardware wise.
You always have to consider that the Wiis CPU is the same as the Gamecubes, except with a higher clock speed. That means the Wiis processor is from a generation that is ~12 years old. Also the Wii only has 88MB RAM. For emulation you need mostly provessor, but RAM also plays a role.
Besides the Wii emulates N64 games just fine. Majora's Mask has less lag on the Wii than it has on the N64 and that is a RAM-expansion game.