Obliterators are, without a doubt, one of the coolest things about the Chaos Space Marines Codex. They are basically two wound Terminators that can all carry any heavy weapon you might need. Want to mow down hordes? Oblits can do that. Need to bust a Landraider? Oblits can do that. Anything in between? Oblits can probably do that too.
Attractive models? Oblits don't have one.