The best costume I have seen, which in fact was quite easy to do was the man going as BA Baracas (Mr T).
He got blackmans skin paint from a joke shop, a swimming hat coloured the same and had toughs of his own hair coming from a slit in the top. A stick on beard and loads of garden chains around his neck with somecheap clip on earrings from a charity shop. He wore old overalls with the sleeves cut off and monkey boots. Very effective.
You could goes as Amy (also from the A team, with eighties hair, and a cheap all in one (lets get physical) jump suit.
Alternatively, you can buy werewolf kits from joke/fancy dress shops and ebay and go as Teenwolf 1 and Teenwolf 2. They take a bit of prep, insofar as you have to stick the facial hair on, but very effective.