The only really funny newspaper strip nowadays that I have read is Pearls Before Swine, which, while not a winner every time, is frequently surreal enough to make me laugh. I still read "retail" and "dilbert" though, for the occasional laugh.
To be honest, I think the problem with the newspaper comic page is that it is so much more uptight than most other forms of media. The people on it usually can't swear, shoot guns, discuss most current issues, talk about things that are controversial, etc. Steven Pastis (the guy who writes pearls) has discussed these things occasionally, which is one of the reasons I really like his stuff. I think the strip that stands out to me the most is the one where rat has a dream that all forms of media are being dismantled because no new blood can get in the field and consumers are sick of experiencing, say, "Gone with the wind" for seventy years. Then rat wakes up and screams when pig hands him a newspaper.
To me, that sums the entire problem with newspaper comics in a nutshell, that most of the comics are just too old and have said all they need to say. I mean, blonde is like, seventy years old or more (IIRC it started before the great depression), peanuts is pushing fifty or sixty (and the creator's dead, so they run reruns rather than letting it die with dignity) then there's hagar the horrible, frank and ernest, prince valient, dick tracey, luann, garfield, rose is rose, family circus etc etc etc. More comics need to be retired, but i suspect that until the end of newspapers the stagnation will continue to be a HUGE problem.