warrenellis - comic book / sci fi writer
alyankovic - Wierd Al
thesulk - funny, don't know him
DearAnyone - funny, don't know him
tonyrobbins - inspirational, a bit preachy / advertising too much at times
andylevy - funny, political
FakeAPStylebook - very funny
mental_floss - neat facts
JimNorton - funny, filthy
ThatKevinSmith - funny, filthy... sometimes posts WAY too much
CSLewisDaily - inspirational, Christian
ConanOBrien
pennjillette - funny magician, atheist and liberal/libertarian
TheRealStanLee - old comic writer
Discographies - snarky summaries of artist discographies
LisaLampanelli - comedienne, funny and dirty
zepadeedoodah - funny, don't know him
Broslife - Barny from HIMYM
Those are some of my favorites. If you tend towards the liberal and enjoy a bit of political humor you may also enjoy Sarah Silverman and Michael Ian Black - both very funny but grated on me when they got political - your results may vary.