best bang for your buck, easy to setup, easy to use, portable, and will run off a standard 115v outlet.
http://www.northerntool.com/shop/tools/product_200471413_200471413
i bought mine in 06 and welded everything on my past 4 jeeps with it, frame stiffeners, suspension links, brackets, bumpers, frame plating, motor mounts, drivetrain parts, etc. Never a failure.
I do use 2 or 3 passes on some of the thicker/ more critical stuff though. A more powerful machine would be nice, but I'm in no rush to get a new machine at all.
Sometimes this place has re-conditioned welders in stock for significantly less (what i purchased) I would have guessed it was brand new, zero signs of use on it.