I didn't find plain, unflavored whey to taste bad at all. Not enjoyable to drink, but nowhere close to bad.
I'm sure if I did anything more exotic than mix it with water, it would be virtually tasteless.
I always feel bad for the UPS guy when I order 50lb bags. Make instructions to just dump it by my mailbox so he doesn't feel obligated to carry it up my walkway and shit in the event I'm not home.