My new favorite comb for getting out mats is the Chris Systems Buttercomb #006. I bought this at a dog show recently and it is a miracle comb. I've tried everything, from the blade matt combs to human eyelash combs and just nothing, nothing would work. This is a great comb because the tines won't bend back or break. It's pricey but totally worth it. I also like to use it in combination with Bo Derek's Bless the Beasts Fur Pomade.. it's greasy but a little bit makes the mat break up a lot easier. You can buy the Bless the Beast stuff for cheap @ QVC.
Chris Systems Website