Top Ten Electronic/alternative Albums

I'm not entirely sure what you mean by 'alternative' electronic music. I guess I don't know if you are asking for one category or two. Since you did not give any examples I'll just take a stab at it assuming it is one category, though I don't know if I can come up with ten right off hand.

Fatboy Slim, Better Living Through Chemistry
Propellarheads, Decksanddrumsandrockandroll
The Crystal Method, Keep Hope Alive
The Crystal Method, Vegas
The Chemical Brothers, Dig Your Own Hole
The Art of Noise, In No Sense, Nonsense!
The Art of Noise, Into Battle with The Art of Noise
Many of Ambient Music Series from Brian Eno - my favorite is probably "Discreet Music"
Laurie Anderson...too many to list here...Been enjoying "Bright Red" lately. "Big Science" and "Mr. Heartbreak" are classics!
Moby, "Play"

That's actually a few more than ten. Still not sure about your category though. Perhaps you should make it more clear, or give your own examples.

Marco

Crystal Method : Tweekend Deep Forest : Music Detected Kraftwerk : Tour de France Dirty Vegas : 1

Not sure if they fall within your requested category, but Massive Attack has put out some interesting material.

Some Electronic and Alternative classics, trying to stay away from the uber-obvious:

Alt:

Sonic Youth "Daydream Nation" - a prototypical indie album

My Bloody Valentine "Isn't Anything" and "Loveless" - texture guitar with androgynous vocals. Yielded the term "shoegazing"

The Cure "Head in the Door"

The Makeup "Sound Verite" - I am always at a loss of words for this band, but the bassist is the best looking woman alive.

Ministry "Psalm 69" - although I am hesitant laying this heaviness on audiophiles.

The Jesus and Mary Chain - "Psychocandy" - MBV precursor.

Jane's Addiction "Nothing Shocking" - Chili Peppers meets Metallica

Electronic:

Lords of Acid "Lust"

Aphex Twin Selected "Ambient Works 85-92"