I'm definately in the "prefer hiking in long pants" crowd. I got so scratched up and hacked up in my youth, and just got tired of it. Plus, as you said, the sun and the bugs.
I really like the zip-off pants by Columbia. The zipper is enclosed on both sides - I mean, there is a flap so that the zipper itself doesn't rub against your legs. Whatever brand you look for, try to make sure that it has that for the zipper. (Alta, it's still nice to be able to zip off the legs when you get back in the car and go for a latte
)
Generally, I look for fast dry pants with a way of fastening the cuffs tighter (again, bugs), one or two zip pockets (for car keys!!) and a cargo pocket. I usually try to find a tough nylon weave fabric because I'm tired of snagging thinner fabrics or knits. A good fabric (for me) will let things like thorny branches slide past it. Otherwise I get hung up!
I also like pants that have some sort of articulation - meaning, that for a weave fabric, there are seams that allow for comfortable bending at the knees, etc.
I never go outdoors in cotton anymore, and definately not jeans. Been there, done that. Yuck, chafing, and if you get wet you're wet forever.
It's not so much the brand, for me, but the slightly techy features.