I'll swear by
GT. Very well made with excellent components.
But really, most major brands are pretty good. Look for one that has the features you want, and
comfortable controls. That makes a big difference!
Definately folow Kuasimodem's advise about looking for last year's models. Often the only thing changed is the color choices!
They've got these all the time, but they only push them during "clearance" events. You could save $100 easily,
but you have to ask!!
Oh, and I'd recommend keeping an open mind as to type & style. A few years ago I bought a hi quality mountain bike, pretty nice rig. Only catch was that after a couple hours I hated the thing! Bought a "cross" style instead & it's MUCH nicer for our usage.
But then, you're a bit younger...