I can't say it's the best, but here is what I don't leave home without:
Hi-Lift Jack
Blocks of wood (to put jack on in soft ground)
Tow strap(s)
Quality, heavy duty come-a-longs are great but you can use the Hi-Lift the same way. Also, make sure you have good tow hooks front and rear to hook to.
Most importantly, don't wheel alone.