Pretty much any old EOS lol. There are pretty much no incompatibilities as the mount was fully electronic from the start. The very oldest may not work with IS, but it has to be really old as IS was introduced way back in the 90s.
I think older EOS 1 cameras aren't that expensive though you get older AF without a bunch of points. Second revision was the 1N which isn't that expensive, but only has five AF points. The 1V was the last one and got a much improved AF system, but it is quite expensive. The EOS 3 had that same AF system, but is also expensive.
Back then EOS 1 was the highest end camera, but it wasn't quite like the EOS 1 is today. Now we have 1DX with a fast sensor and shutter and 5D being smaller and higher resolution. The EOS 1/1n/1v was kinda both as it could be compact high end with the standard battery holder and huge machine gun with the battery grip and extra motor drive.
One notable camera is the EOS 5, known as A2e in North America,
which was the first with Canon's famous eye focusing. The EOS 3 also had eye focusing, but the EOS 5 is much cheaper.
There were plenty others and like today more numbers in the name means lower end model. Lower end film bodies of the area are quite plasticy by today's standards and can be noisy, but work well otherwise. The exception is the EOS 650 which isn't as low end as the name suggest; it was the very first EF camera and was more mid-range with 4fps.
For something more modern, but still cheap the EOS 30/Elan 7E seems ok with dual dials.
