I'd say my own but that would be cheeky lol. I'm pretty fond of these I have on my favourites list:
CER at the Nurburgring (love those BMW M1s!):
http://www.youtube.com/watch?v=Tet45fvnTaI
6 Hours at the Glen from '01:
http://www.youtube.com/watch?v=W6q3DzkLFPI
ALMS 2003 Mosport:
http://www.youtube.com/watch?v=PXDRaiBlltU
ALMS 2004 Mosport:
http://www.youtube.com/watch?v=PPwN7zE7g5U
http://www.youtube.com/watch?v=UGKk2PbCrY4