I have been a welder for over 30 years and I have the pos $99 Harbor Freight stick welder.
I bought it for one reason only. Cheap. The only things I need to buy to use it are electricity and rods.
A MIG is the easiest to use, but requires bottles, tips, wire, and rollers. It is therefore more costly to use, especially the gas which can only be bought at a welding supply.
The fluxcore MIG is the cheaper version but is messier and leaves a nasty looking weld even when working correctly, but only requires tips , rollers, and wire to run.
A TIG is the best quality, most versatile welder. You can do almost any metal joining with the right process using a TIG. But it requires the most skill to use properly and has the most expensive consumables.TIG is, hands down, the preferred style for top quality beautiful welds.
So it all boils down to two things...
How much you can spend,
and how much you are willing to practice.
Need it only in case? Buy the cheap HF stick or fluxcore mig.
Looking to build beautiful, stunning, world class art stuff and get creative? Buy a good TIG.
Somewhere in between? Buy as good a brand (Miller, Lincold, ESAB) MIG as you can (or want to) afford..