I had to look up the track listings on those. Couldn't remember what was on them (except for the obvious big radio hit from each). Short breakdown:
Top Gun:
Sorry, Kenny Loggins fans, but Danger Zone doesn't really thrill me. Not a bad song, but not a great one either. It was really catchy, which is probably why it got so much radio/MTV play, but if I never heard it again, that'd be fine by me. So this soundtrack really just boils down to the fact that it's got two really good songs by two really good '80s bands: Berlin and Miami Sound Machine. And that ain't bad.
Iron Eagle:
I looked, and I don't know a single one of these songs. But I know a lot of the bands. Queen. Dio. Helix. What's not to like?
Karate Kid:
I had to read the track listing 3 times, and I'm still in disbelief that Cruel Summer isn't on there. How on earth did that get left off? What moron at the record label said, "yeah, Bananarama are okay, but these other songs are better than theirs?" I'm eliminating this one from consideration just on principle.
Rocky IV:
Eye of the Tiger is a gimme. Nobody in their right mind could honestly dislike that song. And you've got James Brown (Living In America) as well. This one is a solid contender (no pun intended).
The verdict:
Rocky IV. Each of these only has a handful of songs that I really remember and like. And sure, Iron Eagle has more metal on it. But EOTT and LIA are great songs. Unfortunately, I voted already and voted for Iron Eagle. But as I was typing this, I talked myself out of it. So imagine this poll with one less vote for Iron Eagle and one more for Rocky IV.
Oh, and I would have voted for Batman. Love him or hate him, but Prince is a musical genius by any standard. He was kind of hit and miss for me over the years, but the Batman soundtrack fired on all cylinders. Great album. I also would have picked Purple Rain over any of the above if that had been listed.