Some thing or situation that is so cool, so very perfect, so impressive, that no one could ever concieve of it as fucked, or fucked up, or all fucked up; or say about it "Fuck that." It's too good. It can't be fucked. It's unfuckable. From the Russian nev'yebenno.
Did you try the spicy spinach dip? It's so good it's unfuckable.