Bambooyah (Mashup Mixtape) - The White Panda -- Follow the link to their facebook page and follow the instructions to get this mixtape for free. I guarantee you won't regret it, these could well be the best mashes of 2012.
United States of Pop 2011- DJ Earworm -- If you don't already know, Earworm is famous for creating mega mashups. This is his latest with 25 of the most popular tracks of 2011. A bit cheesy but everyone loves a bit of cheese on new years eve.