It all depends on how serious you are. I got back into biking a couple years ago with a crappy hybrid/comfort bike. Those bikes run 500 or less normally and are useless for rides over about 15 miles. Once my endurance built up and some fat came off I bought a nice road bike. I could go up to 50 miles at a time then - cost was 1900. It's very taxing on my neck, low back, and hands though.
Now I also bought a recumbent bike, which lets me go as far and as long as I want, very comfortably. However, they are not cheap. I switch back and forth now depending on wether I'mracing or not. The hybrid got sold within months of buying it.
If comfort is your main factor, just spend the $$$ and go recumbent. So-called "comfort bikes" really aren't.
Brands are generally fine, so long as you're buying from a bike shop and not wal-mart.