I'm in the market for a good entry level welder. I mostly just want something to fool around with whenever I feel like it, but I want versatility.
Disclaimer: I am not a professional welder, nor do I play one on TV - I only dabble with welding from time to time...that said:
If you want versatility, you're going to end up with multiple welders; there's no real way around that. But, for just "messing around", if you have a dedicated source of 220 AC available, then a classic Lincoln "tombstone" AC/DC welder will do just about everything you'd want and more.
I really don't want to keep gas around, or buy any when I run out. So I guess traditional MIG and oxy-acetylene are out.... someone said gas-less wire can be bought but it is not worth the money.
I've never used wire-feed welders, so I can't really comment, but from what I have seen of others using them, just like any other tool it depends on the skills of the person. You can think of a flux-core wire welder as a stick welder in which the stick "never" runs out (ok, it does, but you know what I mean). You also don't have to generally worry about feeding the material in like you do with a stick welder (where you have feed, "stir", and move all at the same time; tricky to do, but it is what it is). Whether it is any better or worse than a shield gas welder, I don't know.
I want to be able to mess with anything (or almost any) material I run across, including thin-gauge material. So I am guessing stick welding is not what I am looking for.
Depends on what you mean by "thin gauge" material. A good stick welder (or even a crappy one, like the cheesy old AC buzz-box I own), with the current turned waaaay down, and small 1/16" sticks, you can weld pretty thin stuff; I've done bicycle tubing before. You can do thicker stuff with multiple passes, up to a certain point (I would never attempt to weld 1/2" plate with my cheesy little welder - even though technically it's possible, it just isn't practical).
Now - the thing about an oxy-acet torch is its versatility; I've only ever learned how to cut with one, but it is also possible to braze and weld with it too, among other uses. It just isn't great from a storage standpoint (you don't want to buy the little tanks, either - you'll be refilling those things all the time).
I've honestly found that my cheapo little buzz-box AC stick-welder that I picked up off of Ebay suits me fine for everything I've needed it for (mainly "around the house" jobs and minor project work); in theory, I could even use it as a "cutting torch" and for brazing if I used a carbon rod with it (but I've never tried it). It plugs right into the wall, and I use 1/16" rod with it. Its biggest problem is "sticking" of the rod when starting, but that is pretty common with AC welders. You can't really do heavy-duty work with it, but light repairs and similar kinds of project work have been easily done. If I had the money (to get a dedicated 220 line run), I'd definitely have one of those Lincoln tombstones set up (and probably not a recent model, but something older off of craigslist or such).