My two cents on this comics-snobbery tip:
Diesel Sweeties I read because (a) it is updated daily and I seem to have made a habit out of it and (b) it is very occasionally funny. I hate myself for reading it, though, because every single one of its characters needs to be pounded in the face with a shovel until they are dead. And I imagine (where "imagine"="infer based upon admittedly and happily limited experience") that the lion's share of Diesel Sweeties fans are shallow and insufferable in the exact same goddamned ways as those characters. OH HO, SEX PUNS AND INDIE ROCK! I WILL FORWARD THIS TO PEOPLE WHO MAKE ME FEEL COOL FOR KNOWING THEM
Garfield is a one- or two-trick pony, but occasionally those tricks are very good indeed. I'm not going to defend Jim Dav^H^H^H Paws, Inc's entire fuck*ng oeuvre like I would Peanuts (which, even when repetitive, felt cumulative and alive), but boiling it down to "I hate Mondays ROFL" is sort of missing the point, which is one-liners you can smirk / smile / laugh at and relate to.
Plenty of print comics are great, you incredible assholes. (Offer not valid where the reader is not, in fact, an incredible asshole.) I refer you to Pearls Before Swine, Get Fuzzy, and Monty - for starters. Foxtrot, Calvin and Hobbes, and Peanuts were already mentioned, have stood the test of time for years, and don't need my jerkwater defense.
Achewood and Penny Arcade are similar, in my opinion, in that they would be nowhere without the sharp writing. As we've batted around before, Achewood is the output of a writer who happens to create comic strips. And Tycho's literate and witty news posts are the best reason to regularly read Penny Arcade. (Compare with certain other news posts that boil down to "someone on some other website doesn't like me {link} but I'm far too cool to be at all bothered by it -- P.S. Looks like we wanged their server LOL")
Generally speaking, I like to like things, and I like to tell people about things that I like. With a few exceptions, I can't understand why people get so frothy about popular entertainment, as though the idea of many people at once enjoying any given Thing is just intrinsically incorrect and nauseating. I mean, ripping apart a Jerry Bruckheimer movie is one thing, but Family Circus makes grandmothers everywhere smile with a warm and reassuring feeling of recognition.