Amani576 gave you good leads. Now you have to look for an individual specimen. Get a decent model with good frame material, higher-end components, and a size that fits you. Your best bet is a bike that someone bought "back in the day" with the intention of riding it, but soon lost interest in cycling. Near perfect paint, and just needing a cleaning and a good lube job. A little research and patience will go a long way. Also, try to be careful on what you spend. Many bikes being advertised now seem to be grossly overpriced, and most likely will need additional money to be put into them (tires, brake pads, etc.) Even after making a purchase, you can always grab something better that comes along later. That initial purchase will still give you something to ride, and can be sold later. Try to avoid "Frankenbikes" that have been changed from their original specifications and repainted. IMHO...best to stick with a good quality, no-to-low mileage bike with all original parts.