Archive of the former Yahoo!Groups mailing list: The Mellotron Group

In terms of "...Mellotron drenched albums..." it depends how drenched they are. In terms of EVERY track having 'tron on it, then it's "Pampered Menial" by Pavlov's Dog - a brilliant album with brilliant vocals (which I know turns the stomachs of at least 2 forum members!)
Ignoring "My Tron Top Ten" on Andy Thompson's site (which I'll have to change), honourable mentions I give to...
"Starless" (on "Red"), "The Fright Watch" segueing into "The Talking Drum" (on "The Night Watch" album) and "Bartley Butsford" segueing into "Exiles" (on CD3 of the "Great Deceiver" album) by King Crimson. In my view, King Crimson have made the greatest Mellotronic contribution in terms of quantity (over 50 of their albums have 'tron) and quality to this world of Rock that we inhabit.
You can also add...
Genesis - "Watcher of the Skies", with THAT intro,
Jethro Tull - "The Witches Promise",
Mike Dickson - "Stroke #2" (on "Six Consequences")
Edgar Froese - "Macula Transfer",
The Groundhogs - "Earth Shanty" (on the "Hogwash" album. Not much tron, but very effective), and...
Sparks - "Thank God it's not Christmas" (off "Kimono my house". Same as for Groundhogs)