I would eat regular, chicken, or musical mushrooms. Those look the most like "real" mushrooms. It'd be great if the mushrooms could keep their color after cooking, too.
While i love booton, i don't think i could eat anything that looks like it's looking at me while i eat it. So all the faces are out. If it looks like it's trying to run away, that's also no, so scampering types are out.
I love Toblerone, but maybe not in a mushroom. And while the paint shrooms might look ok to eat - I've mixed a bunch of paint colors up before, and it just looks like dark gray mud. Who wants to eat mud? Not me.