They are good cars. I have had two. First thing is to try and get a good understanding of how many miles it has on it. This is not always easy considering that it most likely has a faulty odometer on it. Check into that.
Second is its idle control system. Does the car idle? If it does, then great.
Get a manual. Check the syncros on 2nd gear. Is it hard to shift? Does it grind at all? Second gear on these transmissions seemed to wear more than the rest. Mine is slightly worn, however I switched to Redline MTF fluid in the tranny and all problems have vanished.
Check the fuel system. Does the car start right away? Are there any strange buzzing noises from the fuel pump?
The engine is going to tick like a singer sewing machine. That is normal for the most part, unless it is extremely loud.
Take a look under the oil filler cap. Be sure that there is no gunk in there. It should be clean and shiny. Amber color on everything is ok.
The seats. They have notoriously bad seats. Not many ways around that.
Most of the things I listed should not be deal breakers. I got mine because the owner thought its timing chain broke but it was really a distributor rotor. Protip: make sure your battery is secured or else it will hit your distributor and break the rotor
So when shopping, just keep an eye for the things I mentioned and assess their severity. They are all easy fixes for the most part and once repaired will net you a very reliable and cheap vehicle.