This is an open question....it completely depends on what you're going to use it for, or what you want to use it for. It also depends on what shape the machine is in. I think that if I was in the market for a stick welder, I would look at one of these machines, but I'm biased to the blue colored welders myself.
Stick (or arc or SMAW) is a relatively hot weld. It is a versatile form of welding, and when done properly...can produce some very strong welds. You can get different types of rods for different types of metal. Usually alot of cleanup after welding is needed, but this form can be used in almost any condition (inside, outside, windy, and even underwater).
I personally prefer MIG (GMAW) welders. They're fairly easy to learn on, and can produce some very strong welds as well in the hands of someone who knows what they're doing. MIG can be used in various conditions as well, but in windy conditions a flux cored wire is recommended as the shielding gas gets blown away. I have a Millermatic 211 running .035 wire with a 75/25 C02/Argon shielding gas. I really like this setup, and is what I'm using to build numerous projects including a solid axle swap.
If I had the money, I'd love to have a TIG setup in my garage....but that will have to wait for a while. TIG has the most control over the various forms of welding, and can be used for anything from very thin-to fiarly thick metals. It can also be used to weld specialty metals such as titanium, inconel, stainless, aluminum, etc. It usually used in controlled situations, ie...little wind flow to keep the shielding gases flowing properly.
Check out
http://www.weldingweb.com for a ton of info and great resources. Seriously though, if you want to learn welding...take a course on it. I'm sure that there are beginner courses that give an introduction to welding around you, usually a community college or specialty school.
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