The Gutenberg Project has digitized a number of Doré's illustrations. UPenn has these editions online, the image quality is decent. Linking to the list of the books is a different problem. The below URL, copied and pasted to a browser address box, should work:

http://onlinebooks.library.upenn.edu/webbin/gutbook/author?name=Dor%26eacute%3b%2c%20Gustave%2c%201832%2d1883

If you click it (from the blog; dunno 'bout aggregators), I doubt it will work.

Below is a sample illustration (I've decreased the size for presentation here) of Dore's from Dante's Vision of Hell, Purgatory and Paradise, part 2.