I really liked an older True Temper I had that was made for the US Army. I ended up selling it to a collector.

Now I like the newer Ontario Knife Blackie Collins designed ones and if I was buying a new one I would likely look for one with the full knuckle guard (D handle). I find the handle design with those more comfortable, which is one of the things I didn't like with the rather square section plastic handles on the Ontario Knife machete.
http://www.ontarioknife.com/machetes.html

I like the lighter but longer style of blade too instead of the heavier versions. I find they swing easier and bite deeper into most wood.