I'm probably going to kick myself for making this thread, I find it very unlikely that this hasn't been done before, but after a handful of searches and no results... well.
There's a website that makes building a top 50 (or top 100) album collage very easy. It has a built in search engine with an impressively large archive of albums + album art, making the whole process a lot faster than it would be using Photoshop. Take some time to comb through your collection, throw together a quick list, it's really only the first 20 albums that are significantly ordered.
Topsters.net - Top50
It's more fun than work, you stumble upon a lot of old albums you haven't listened to in a while that you absolutely love. It's nice having one of these collages laying around too when you're looking for something to listen to.
Keep in mind that my ordering here doesn't say much about the literal quality, legacy, or historical significance of any of these albums. It's purely ordered by personal taste, it's about how often I find myself going back to listen to an album, it's based on my personal experience with each album and the memories I associate with them, not their overall importance in the musical world.