There are so many options when it comes to buying film SLRs. What I would say is that selmerdave is absolutely right in recommending that you look for used cameras rather than buying new. Film cameras, not only old mechanical ones but even the most modern ones, are less reliant on complex electronics than digital cameras so there is less risk in buying used. And as said the prices are incredibly low. You could get a modern fully featured multi-mode SLR, or a classic mechanical one; it all depends on what you're looking for in a camera.
Some things to consider when choosing an SLR system are the availability of lenses (new or used), the cost of the lenses, and whether or not you want to be able to use the lenses on a digital SLR in future since this is possible with some old lens mounts but not others.
Some things to consider when choosing an SLR system are the availability of lenses (new or used), the cost of the lenses, and whether or not you want to be able to use the lenses on a digital SLR in future since this is possible with some old lens mounts but not others.