Magic: The Gathering. Wallpaper of the Week Archive (up to 19.11.2014)
The full collection of wallpapers from the official site.
Mostly contains only the biggest images for each of an available aspect ratios.

All wallpapers are sorted by aspect ratios in separate folders:
1024x768 (4:3) - 181
1280x960 (4:3) - 497
1280x1024 (5:4) - 353
1600x900 (16:9) - 1
1600x1200 (4:3) - 37
1920x1080 (16:9) - 158
2560x1600 (16:10) - 369