I used to read the paper religiously in high school, so I have fond memories of comic strips:

• Mutts

• Calvin and Hobbes

• Frank and Ernest

• Far Side

• Red Meat

• Pockey the Penguin

• Doonesbury

• Mother Goose & Grimm

• Foxtrot

When I worked at the library desk at Caltech I wrote a perl script that let me call up all the Doonesbury strips from their official site, one year at a time. I spent three or four hours getting an education in American political and cultural history of my parents' generation (my high school US history teacher skipped that part).

I tried to get into Bloom County, but I never "got it". I was out of the country during its prime.

I don't know anything about web comics (except that I was never bitter enough to understand Sinfest). You'll have to ask John about those.