Ann,

I have to agree with Sen, that most hybrids are the worst of both worlds. I had an old Royce Union mountain bike when I starting cycling and I went out and bought some light-weight alluminum wheels and thinner road tires. I would switch the wheels around for road rides and mountain rides.

That said, there is one fairly decent hybrid that I bought for my wife. If you are doing mostly road riding and some very mild mountain biking, there is one that is a pretty good bargin at only $399:

The Marin: San Rafael.

Key point here is very light mountain biking, like staying on fire roads. My wife rides centuries with me and does just fine on her San Rafael. She prefers the feel of the mountain bike and the softness of the suspension.

Jeff