What kinda points level are you playing at? Dark Angels are great for Azrael, giving a massive blob of guardsmen with fearless and a 4+ invulnerable save, chuck in a load of flamers for overwatch. I'm not too knowledgeable about
RW and
DW but I've got the impression the general consensus is that
DA aren't a
CC army, as that seems what you're after.
BA aren't really a
CC army anymore, they're more mobile and shooty. Space wovles and
IG are awesome. Psyker battle squads using weaken resolve and
SW Rune Priest with jaws of the world wolf with destroy any threatening
MC's

anywho, I'd recommend space wolves.