I've never been into soundtrack albums much because they usually have just one (or maybe two) really good songs, and a boatload of trash (even more so than normal albums). However, there were a handful of soundtracks back in the 80s which reversed this and had all or nearly all good songs. These are the only soundtracks I can think of which I enjoy listening to from beginning to end, only skipping one or two songs at most;
Footloose (original 80s one, not the remake where they butchered the music)
This soundtrack is of course iconic, classic, and epic. I listened to it constantly as a kid.
Here Comes Garfield
I got this around xmas back in the mid 80s & listening to it somehow became a holiday tradition.
Transformers: The Movie
The orignal TF movie, the animated one, the only good one. The music in that movie was awesome. I watched it for my 11th birthday party & was blown away at seeing a non-preschool-ish animated movie and at seeing a movie with such a rocking soundtrack.
Rocky IV
The best of the rocky movies, and some of the best music.
Who Made Who
The soundtrack to the movie Maximum Overdrive, performed by AC-DC, 'nuff said. :p
What soundtracks do they rest of you like in their entirety?