Personally I have a soft spot for newspaper strips, especially Calvin and Hobbes--that was the first strip I ever "read." (My parents owned The Essential Calvin & Hobbes when I was super little, and even though I couldn't read yet, I remember looking at the pictures and making up the dialogue.) As I got older and more educated I learned to appreciate the strips with bigger words more, so it's something I enjoy more and more.
I also like Bloom County and Pearls Before Swine. Get Fuzzy is pretty good as well, though I haven't read it for a while.
As far as non-strip comics, I like the Finder series, by Carla Speed McNeil. The Less than Epic Adventures of TJ and Amal is a really awesome webcomic, which you can read if you're interested. And as for other manga, I like Parasyte, Fullmetal Alchemist, Yotsuba&!, and Flowers of Evil. Yu-Gi-Oh is high on my list for the nostalgia value, haha.
Ultimate Spider-Man, with Miles Morales, is the only Marvel title I follow/subscribe to, and I don't read any DC comics.
These days I've mostly been reading Tezuka's works, so I can't name many more titles off the top of my head. How about you folks?