I used to be an avid comic strip reader, but stopped getting the paper many years ago, and I use my online time to keep up on ridiculous *ahem* internet forums. Most of you have nailed my favorites - Bloom County had to have been my earliest fav, followed by The Far Side. Calvin & Hobbes & Get Fuzzy were both awesome, and gave me some of my best laughs. My biggest laugh, though, came from a strip that I wouldn't say was my favorite, but the one strip struck me in just the right way that even now *mumbledy* years later I still chuckle over it. I did an image search but came up empty.
The comic was Robotman, which evolved eventually into Monty. In this particular strip, Robotman is leading a group on a hike, following a compass. In each panel, Robotman realizes he is going the wrong direction with a "wait, no, north is THIS way". In the final panel, Robotman says "No, wait, north is directly up my nose", to which Monty says "The lesson here is to never give the compass to an overgrown kitchen magnet". "North is directly up my nose" has become my way of saying we are hopelessly lost, either literally or figuratively.