One thing that seems to be working really well for our stubborn daughter is giving her "tickets" for good behavior. When she's misbehaving, we'll say something like, "You have three tickets right now, but if you lose all of your tickets, you won't be able to get dessert." This gives her some wiggle room to make some mistakes, but most of the time she gets it together and keeps at least one ticket so she can have her dessert or toy or whatever. The tickets aren't even real (but I've heard you can do the ticket thing with real tickets), but she collects them and seems to do what we say because of them.
Besides being a dad, Michael Ian Black is best known as an actor, comedian and writer and has starred in shows such as Comedy Central's Reno 911! and VH1's I Love the '80s ... series.