The New Adventures of Old Christine(CBS or NBC?): ******** awesssssomeeee. I love Julia Louis Dreyfus and not just because she has the same name as me, lol
Leverage(TNT): My mom got me in to this show and after we found out it got cancelled and watched the last episode we immediately made an online petition to bring it back and we had more than like 2,000 signatures so we sent it in an email to headquarters and their Facebook account to no avail xD we also found out there was an even bigger petition so we just quit.
United States of Tara(HBO or Showtime?): Great acting and script. Highly recommend if you happen to see some episode online.
Brooklyn Love Story(ABC): Recently cancelled even though it was a perfect show. I shipped the two main characters so hard!!
Bad Judge(NBC): Still airing but already set to be cancelled soon. Pretty funny!
That's basically it except maybe a few cartoons but I haven't experienced much cancelled shows since I mostly seem to watch ones that stay on.