Depends on space and budget. Which one is the limiting factor?
Steer clear of cheap Chinese made stuff (this includes the likes of Clarke, Draper, Sealey, Warco etc). A good, used English made machine (from the good old days!) will be far more use than any of them. Make sure the lathe you get works on 240v - larger ones often require 3-phase electrics (unless you happen to have 3-phase in your workshop...)
If space and budget are available, something like a lower end Boxford, or a Harrison would be a very good machine (they're big and heavy, but that's good in a lathe!)
At the smaller end, Myford are the go-to choice of folks with enough cash to spare. They're not cheap, but they are reasonably accurate and rigid. They also have the best aftermarket support (try buying spare changegears for anything else!). ML7's are mysteriously well regarded, but the design is from the 1930's. The design was updated in the 50's, and relaunched as the 'Super 7', and it has changed very little since then. It uses drip oilers for the bearings (regular ball bearings), they need to be topped up etc etc. Their later ML10 model is a bit smaller, but still OK for most jobs, and has taper roller bearings which use grease instead of oil, and needs far less maintenance.
Screwcutting is a good feature to have on a lathe, most will be capable, but some smaller ones might not. Back gear (another name for a really low gearing to enable low speeds with high torque) is really handy. All lathes should come with (as a minimum): A 3 jaw chuck, a 4 jaw chuck, a faceplate, chuck key, a carton of oil for the bed (if not, what were they oiling the bed with???), a set of changegears, some lathe tool bits, and the electrics should have an emergency stop button (not always the case on older lathes).
Whatever machine you get, you should have a go on it before purchase. Listen for dodgy bearings (in the headstock, tailstock and motor), check the bed has no tight spots (move the saddle along the entire length of the bed - it should have a nice even resistance along the whole length). Check for play in the tool mount - best way to do this is to take a light cut in something hard, like steel. If you see/feel the tool post flexing as the tool bit contacts metal, that's not good. Also check for free play when you move the tool - the gear drives will have a little bit of slack, but it shouldn't be much. The more slack there is, the more the machine will frustrate you as you try to do anything with precision.
Last thing I can think of - most machines will be imperial, which for anyone below retirement age tends to be a pain. If you're comfortable in an imperial world, feel free. Otherwise, it helps if you can find a metric machine (it'll REALLY help with screwcutting).
Once you get the lathe, grab yourself a load of aluminium alloy off cuts to practice on, and (it should go without saying really) for god's sake wear safety glasses. They're a pain, but I'd have lost both eyes at least 3 times by now if I hadn't been wearing them. Oh, and make sure you have good lighting in your work area!
Milling machines are a whole different ball game, although the same applies re the Chinese stuff. At the lower end of the market, milling machines tend to be small and bendy - not what you want really. They get expensive very quickly, so my answer was to get a vertical slide for the lathe, which effectively turns your lathe into a horizontally mounted milling machine. You're a bit limited in movement - maybe 80mmx60 or thereabouts, but it allows many jobs to be done.
Of course, once you have decided and purchased, do get back to us with pictures so we can all drool over your new toy.
Steve
