Very hard to say. Most of my favorite comics as I was growing up were super heroes, but not all. The first one I recall being a favorite was Flash (back in the Infantino days, though I'd certainly been reading Superman and Batman for longer). Other favorites I had over the years in chronological order were Magnus (by Manning), Fantastic Four (in the Lee-Kirby Days). SHIELD (under Steranko), Flash Gordon (briefly under Williamson and Goodwin), Deadman (by Adams), Bat Lash and Anthro, Spirit (Warren/Kitchen Sink reprints). I guess the last one I could think of as a favorite comic was All Star Squadron.
Now I'm more interested in old time comic strips.