This theme is really quite excellent it has a very "Zerg" feel to it. It's the only one that stands out to me. The rest of the music feels really half-assed.
Worst theme in my opinion...
I really dislike a lot of the Terran music this time around. It sounds very "country" or "hick". Almost like you're playing a race of rednecks. I suppose it's fitting given the bad story, style, and acting of the campaign mode. But I prefer music that pumps you up as you play. This music just doesn't do it for me. It makes me feel like I'm listening to Dwight Yoakam.
Now let's look at Starcraft: Broodwar's music.
All of those are my favourite themes taken from each race. The music feels like it belongs to each race, and I feel they're a lot better. I would post Starcraft II songs for comparison but I don't feel that I would properly pick the right songs for comparison since I find them all equally bad. So if you're really interested just look them up on Youtube.
Enjoy high quality sound with these bad-ass headphones.