I'm constantly clearing brush in my back yard, as well as chopping up thick limbs that come down from the 100+ year old trees that surround my house whenever we get heavy wind. I can highly recommend the Cold Steel Kukri Machete for this sort of work. I find that the recurved blade comes in very handy for slicing through the bushes and sapplings that are constantly popping up in my yard, while the upper portion of the blade is excellent for chopping through thick branches the way an axe might. These machetes are very affordable & worth trying. I need to caution you though, you'll need to do some slight modding once you take it out of the package. The polypropelene handles are very aggressively textured, and it will chew your hand up unless you're wearing heavy gloves. Since the poly is very easy to slice through, I just cut some of the textured surface off mine to flatten it, along the top portion of the handle where it comes into contact with your hand between the thumb and forefinger. It's a 30-second mod that will save you a lot of blisters.
edit: The model I've been using is their "magnum" kukri, which has a 17" blade. They also have a smaller version with a 13" blade, though I couldn't imagine doing this sort of work with something as short as that. So far, using the large one, I haven't managed to skin my knuckles yet. *knock on wood*
