You can get some good deals buying used or a dealer's old-stock. I bought my bike for 25% off MSRP that way.
Since I ride Specialized, I'm going to throw out a nomination for the Specialized Rockhopper/Stumpjumper.
If you're only going to go on the road, you may just want to get a road/hybrid or slick tires with good flat protection.
I'm dropping out to create a company that starts with motorcycles, then cars, and forty years later signs a legendary Brazilian driver who has a public and expensive feud with his French teammate.