I had three in mind after I read your original post.
Leading the list was Get Fuzzy. You've already had a couple suggestions for that. You can get it for free at:
http://www.comics.com/comics/getfuzzy/index.html
Another mainstream choice would be Foxtrot, freely available at:
http://www.ucomics.com/foxtrot/
A little off the beaten path is Red Meat:
http://www.redmeat.com/redmeat/
If you are politically liberal, then try Tom Tomorrow (Dan Perkins) writing This Modern World or Ruben Bolling writing Tom the Dancing Bug. If you are not politically liberal, you might still enjoy the occastional Tom the Dancing Bug, but you would have to be a remarkable person to put up with This Modern World for too very long.
http://thismodernworld.com/
http://www.ucomics.com/tomthedancingbug/