I have two. The "hybrid" is a Giant Roam 2 w/ alum. frame, suspension fork, and disc brakes. It is an excellent paved or chat trail bike but not so easy on the road.
The other is a Giant Defy 1 w/ alum. frame and a carbon fork. It appears to weigh about half of the other bike and is a pleasure to ride on hard surfaces.
I'm with some others-stay away from online bikes for a lot of reasons. Most bikes need to be fitted, i.e., the correct frame for your size. After that they will adjust seat height and angle and handlebar angle. Giant bikes come w/ a lifetime adjustment warranty which is nice as cables stretch, etc.
Mostly the bike shops offer a wealth of information on technique, style, safety, group rides if you are interested, plus a variety of necessities.
Wear a helmet, get a flashing strobe for the back, and get a good rear view mirror. This is not the time nor place to save a few bucks on a WalMart bike or one purchased online.
I bought a Cannondale R700 NOS three years ago, I saved a few bucks and have a burnt orange Made in America road bike, I decided that being hunched over in the drops no longer fit my 57 year old bod, I am slightly over 200 lbs, so I bought a 56CM frame and moved all my gear over to it, I may try to make a flat bar road bike out of my old frame, but they are identical, I bought the Honey Badger a Walmart mountain bike, which we still have till she asked me, why did you spend a grand on your bike and 100 on mine. I told her I didn't think you would use it, I didn't think you would take care of it, and I thought you would kill me for spending 2 grand, she said, OH? So I went out and bought her a Giant Rapid 1, a flat bar road bike with an aluminum frame, and a little larger tires, which is perfect for the black-top we normally ride, she loves it, and has sold two more to close friends by her recommendation, oh and hers is baby blue and aluminum, it is a very pretty bike, and I like to ride it myself, but I have been forbidden to touch it, but it is much more comfortable than my pure roadie. So shop around at the bike shops, craigslist, etc, ride as many bikes as possible and you will know when you find the one, the key is to get good advice, and have it fit to you, I fit my bike to me, and my wifes to her, once I convinced the Honey Badger to "spin" on the hills, she hammered me the other day! billy
Oh, and my other bike is a 2001 Suzuki GSXR-1000, it is also blue and white, pristine, and for sale since it is telling my body the same thing, my bod is saying OUCH!, but I will miss the Gixxer, it sounds like the old Indy Cars in the 70s, something about a straight four in a very high state of tune, music!