My first welder was an AC/DC stick unit. It is great for the big heavy stuff and for running nickel rod on cast iron, or for running some hard facing rod on loader buckets, dozer blades, etc. Welding one inch plates will take multiple passes with stick, just like with MIG, and the slag will be harder to clean off of the stick welds. If you need top quality welds you had better practice alot or slag inclusions will be everywhere.
I eventually purchased a MIG unit, running gas instead of flux core. It does 99% of my work and leaves a squeaky clean bead that can easily be welded over for multipass work. I find that I rarely need to weld material thicker than 1/4" and the MIG unit handles up to 1/4" with ease. The MIG unit is also easier to learn to use than stick, not to mention that you have to be very careful about rod storage for your stick welder, or the rod coatings will absorb moisture, ruining the rod.
Oxyacetylene is nice for brazing and silver soldering, or cutting large pieces of plate, but I cannot warrant purchasing one when I can build a propane torch much cheaper. The propane torch will get hot enough to silver solder most objects, and that is usually enough for my purposes.
Now if I really wanted the ultimate, I would purchase a small TIG unit, but I really cannot justify that expense either.
