The ones I watch often are
Ethoslab (the man is a god, but don't try and use him as an example in FTB because he's trying to be unique and using really awkward systems)
Vintagebeef
Guudeboulderfist (not been uploading recently)
AnderZEL (don't watch as much any more)
SethBling
Direwolf20 (Starting to find it hard to finish his regular videos although his mod reviews are excellent)
GenerikB (for the bee stuff, even though his noobiness makes me cringe sometimes)
A few other mindcrackers like Pause that I watch less often and of course the podcast.
In order:
Direwolf20
odedex
KDDMac
Hypno
Ako
generikb
etho