A Harbor Freight Titanium Easy-Flux 125 amp welder. It's a little flux-core machine that can run off a 15A, 120V circuit (although I occasionally pop a breaker with it cranked up). It is more than enough for most jobs welding steel. I've done things like repairing the hinge on the team trailer's ramp gate.

The welder on the garage floor, with its work clamp and gun.
The welder on the garage floor, with its work clamp and gun.