Monstarrrr!!
I do like RedBull too, but only now and then.
Relentless I used to drink all the time but I sickened myself of it.
Rockstar is pretty decent, I like the juiced variety.
Kick is abit cheap and nasty, used to drink it in 1st year of Uni - ALL. THE. TIME.
Cocaine is also rather good, the buzz you get from that is phenomenal for an energy drink!