I'll second that. Angron is the whipping boy for a lot of jokes about being a mindless, Angry killing machine. But it's the why that counts. He should have been able to go out like a champion. Which is why he is my pick.
My least favorite...It's a toss up between Fulgrim and Kruze. Fulgrim is too boring for me. and Kruze...ugh, he went out like a punk. I know it's that whole "Heart of Darkness" thing going on. And I know he's supposed to be batman, or whatever. But his death is JUST SO LAME. "I knew they were coming. So I let them..." whatever bro.