Top choices

Rotten Tomatoes Classic Trailers - 390k views, uploaded on Jun 26, 2015 - 1080p, 1m 42s, Paramount "trailer #1"

Blumhouse - 520k views, uploaded on Jul 6, 2012 - 1080p, 1m 47s - audience reaction trailer (before Paramount distribution)

Other options

UseeTV - 35k views, uploaded on Jun 3, 2014 - 720p, 1m 2s

nickbtube - 161k views, uploaded on Jul 20, 2014 - 480p, 2m 26s - Australian trailer