I'd be hard pressed to come up with a top 10 album list for 2007 never mind top 20 so for this year at least I'll restrict it to my favourite tracks of the year. In no particular order:

Feist - My Moon, My Man
Julie Doiron - I Woke Myself Up
Radiohead - All I Need
Arcade Fire - Intervention
The Stars - Take Me to the Riot
Caribou - Melody Day
Luna - You Turned My Head Around
Rihanna - Umbrella
Dr Dog - My Old Ways
Band of Horses - The General Specific
Miracle Fortress - Have You Seen in Your Dreams
Battles - Atlas
brakesbrakesbrakes - Mobile Communication
St. Vincent - Now, Now
Au Revoir Simone - Fallen Snow

Have to agree with Kyle that the Wilco CD was a disappointment and am surprised to see it on several year end best lists. The Okkervill River, Dino Jr and The Sadies all had records this year that despite the hype never made much of an impact on my listening time.

Don't know if you guys are checking out Pitchfork's year-end lists but I did enjoy their worst album covers of the year.

Other sites with some interesting year-end lists include Pop Matters and Dusted Magazine