I'm probably going to list the albums that I think are best for mostly subjective reasons.
I think they're objectively amazing but that's probably because I really like them.
-Dark Side of the Moon- Pink Floyd (I know I'm not alone on this)
-Plastic Beach- Gorillaz
-Once- Nightwish
-Oceanborn- Nightwish
-Little Dragon- Little Dragon
-No Need to Argue- The Cranberries
-King of Limbs- Radiohead
-The La's- The La's
-Actor- St. Vincent
Most likely more than that, but my memory doesn't want to be summoned for more.
I know if I listened to Blur albums in entirety that at least one of the albums, if not more would find a nice spot on my top favorites, but I haven't gotten to that yet. All I have is a "best of." Which is certainly amazing but I'm sure doesn't hold up to an actual album experience.
Also, since we're posting photos of album covers, here's my favorite: