If you want new, your choices of decent bikes will be very limited, but stay away from the mart bikes. With a $200 budget, you can do very well if you shop the used market. Read these forums to get an idea of what to look for in a used bike. One member is in the process of putting together a guide to buying a used bike. If I find that thread I'llpost it here, lots of good tips in that thread. If you run across what sounds like a fair deal, you can always post it in the forums for feedback on it.
Here are a couple of examples of what kind of deals to look for, pulled from my local Craigslist:
http://dallas.craigslist.org/dal/bik/3101250453.html
http://dallas.craigslist.org/dal/bik/3060067617.html
http://dallas.craigslist.org/ndf/bik/3101253921.html
Although some are listed as "Mountain bikes" the older non-suspended types are excellent hybrid bikes with just a tire change to something more streetish. I have an '88 Trek 900 that works great that way.
Here's an example of what to look out for.. The fork is bent backwards. This bike hit something hard. Otherwise it would be a good buy.
http://dallas.craigslist.org/dal/bik/3101527624.html