As a first bike I like the late 80's to mid 90's non suspension mountain bikes. Most of the name brand ones (specialized, giant, trek, etc.) came with decent components, stable geometry, and a solid frame. Some also came with eyelets (front & rear) for both rack and fenders.

Most of the time you can pick one up pretty cheaply. As a first bike you really don't want to spend a lot of money on something you are not sure you will get into.