In old American iron:

- Monarch (the Cadillac of lathes). You'll see lots of 10EE's on the web in response to a search for a "Monarch lathe" but they're a specialized, tool-room lathe. Monarch made other lathes (which were quite good) for more general-purpose use. A Monarch 15" lathe would be one of my dream machines.

- LeBlonde is a solid, US-made lathe that was never the prettiest girl at the prom, but perhaps the most plain that would get the job done with little fuss. The Regal and Servo-Shifts are usually available all over the US used, at reasonable prices. They're a solid machine, but nothing exciting. They're not super-precise, or meant for cutting an incredible variety of threads. The LeBlonde Regal and Servo-Shifts are machines for which you can still get parts from the manufacture.

- Cincinnati lathes are solid machines.

- In larger lathes, American Pacesetter was a very good lathe - but where they start is bigger than most people want to give a home.

- There are Clausing machines that are pretty good. Clausing had some good machines, and some that came from the factory with problems that you'd eventually have to fix (eg, hydraulic variable speed)

- In lower-priced American lathes, South Bend was an OK machine. Lots of people love South Bends, but the reality is that they were light machines, made more for light work and hobby use.  Some gunsmiths fawn over the "Heavy 10" SouthBend lathe. I shrug my shoulders - the "Heavy 10" is OK, but only that. It's a small, light machine.

If I were to get a South Bend, a "Heavy 13" South Bend would be one of their lathes I would have, especially if I could find one that is 60" between centers. The Heavy 13 is heavier, stiffer and takes up much more room than a "Heavy 10" but it is worth it, IMO.


Some stuff to run away from:

- Acer
- Most ChiCom lathes

Here's something that most people telling you which lathe to get won't tell you: The cost of the lathe is just the beginning of your problems. Once you have lathe, then you start bleeding money into the tooling for it, or you start making tooling for it. Many times, I've told young  guys who are buying their first machine tool that it is better to find a machine that has most of the tooling being sold with it, rather than to try to accumulate the tooling after you've bought the lathe. In other words, if you can find a lathe with the chucks, a collet chuck, a set of collets, a live center, a dead center, a drill chuck and a toolpost, steady rest, follow rest, face plate(s), drive dogs...  that lot of tooling is worth a fair bit more money than just a naked lathe.

New chucks aren't cheap any more, even chucks from China. If an older lathe is missing the steady rest and follow rests... you can make new ones, but it's going to take some effort. 

Here's a great site which catalogs a LOT of machine tools, made all over the world:

http://www.lathes.co.uk/

 
OK, when you're looking at a used lathe, you need to look at the ways just in front of the chuck. This is where most of the wear or abuse on a lathe's ways will tend to happen.  

If you have more questions, I've made my email in my profile visible.