Went to see the strangers last night and it was terrible. Haven't seen Mamma Mia yet buy my mam and my sister absolutely loved it. Don't know if that helped.
Mamma Mia has recieved brilliant response from most critics and audience's everywhere, The Strangers has recieved average reviews and most people haven't seemed to like it.
I don't think much of either, but I'd recommend Mama Mia, you will get more fun out that film than The Strangers... wait till dvd or go and see it with someone else. Take your friend to the musical.