Gaming
Pwnapplez,
PrincejeffyPS3 (Best Graal channel as of this moment),
Yogscast Simon & Lewis,
Yogscast Sijn,
Yogscast Sips,
Yogscast Kim,


Pranks
PrankvsPrank,
Ownage Pranks,

Japanese stuff
Abroadin Japan,
Baka Oppai,
ohohojousama
DEMOLITIOND

Tech
Marques Brownlee (A good tech reviewer),

Music
ENM (just discovered music channel, its pretty good)
xKito Music
dj-Jo / Zenpaku