My vote goes to skyrim. Oblivion was one of my favourite games of all time until I played skyrim, cos it was better in every imaginable way and showed how flawed oblivion really was. Both great games though.
My prediction threads:
Wii U will sell under 40m units (made on 14th September 2012)
PS Vita will sell under 20m units (made on 30th September 2012)
Wii U will sell under 7m in 2013 - I was right