Phat is absolutely right! The best footwear is what fits you and is comfortable for you.

However, I must report that after stubbornly insisting on boots all these years due to ankle issues, I've made the switch to trail runners and am far more comfortable. The trail runners provide support for things like my severe pronation problems, which boots (even with various types of insoles) do not. I carried over 30 lbs for a couple of days last summer (due to sick dog--I was carrying his stuff too), but I never missed the boots!

I also found it very hard to find boots, since very few outdoor stores carry a decent selection. That's especially true in my case with women's boots. All they do carry are goretex-lined, which sweat my feet and, once wet, take days to dry.

Trail runners are best bought at a good running shoe store.