There haven't been any great strips for some time now. Once The Far Side, Bloom County, and Calvin and Hobbs disappeared, what was left? There are still some fairly amusing strips around today (Monty, Get Fuzzy, Zits), but nothing like the strips of old.
Of course, there are some webcomics that are pretty good. Girl Genius, PvPonline, and Something Positive come to mind.
The Far Side. Now that was sad ending.