>>189262090s road bike. Even the entry level (good) ones with exage are very decent bikes, main thing is condition, but it's gonna be worth overhauling it mechanically if you do the work yourself, and parts are cheap and universal in most cases.
So, something with a cassette hub, hooded aero brake levers, cromo tubing and indexed downtube shifters.
If you go older than that, ie, any bike with a freewheel, you should narrow your interest to only high end bikes.
And if you go newer, be very careful on condition, and avoid thumb button STI shifters, bikes with carbon rear triangles, and indexed triples.
For classic and modern bikes the main thing on condition to look out for is non-worn chainrings and getting decent wheels. If they have loose spokes or are badly out of true assume not good, brake track shouldn't be concave, and if the bearings feel rough they probably are shot. An old bike with bad wheels/tires is worth practically nothing unless it's top of the line.
