I think there are a lot of albums that come very close to perfection, but they usually have one song that disqualifies it for me. Foe example, Metallica's ...And Justice For All would be perfect if they dropped "Eye of the Beholder."
I view an album as perfect if there's not a single song that I skip. That doesn't mean it's my favorite album (there's too many to call one my favorite), nor does it mean that the band doesn't have better songs on another album. So...
Metallica - Ride The Lightning... Apparently the band hates "Escape" as they've never played it live. I like it enough to never skip it.
Black Sabbath - Paranoid... The only 'filler' in this one ended up being perhaps their most famous song - Paranoid
Slayer - Reign In Blood... It's about 26 minutes long. No redundancy or fillers. Rick Rubin asked them if they realized it was only 26 minutes long and maybe they should add a track or two. The band said they said everything they needed to say, and the cool thing was you could listen to it all the way through without a break, then flip it over and listen to it all over again (the entire album fit on one side of a cassette).
Stone Remple Pilots - Core... Not a single weak track.
I'd love to include Led Zepplin II, but I really, really hate "Thank You."