Depending on (again) what the rest of your requirements are--what *kind* of shooting you'll be doing--I'd either second the suggestion of an off-brand M42 or K-mount SLR (plentiful cheap glass available everywhere in the world), or something like a FED-3 (M39 lenses of all kinds are likewise easy to find, and if you're shooting mostly wide this will make for a smaller, lighter, simpler-in-construction kit).

If changing lenses is going to be impractical, then screw it and get a cheap plastic SLR with a zoom lens like others have said--people are essentially giving them away for free.