The edelbrock. The stock manifolds are not that bad. Some of the earlier models had stock type 4 barrel manifolds. Not performance oriented at all though. Or did you mean which carb?
The truck avenger is arguably the best off road, but pretty expensive. Any 4 bbl for mileage is going to depend on keeping your foot out of the back two barrels. The motorcraft 4 bbls are pretty good off road and can be had fairly cheap used, but not the best performance carb. The edelbrock 1406 carb is good for performance, but not great for serious off roading. Q-jets are real good, but very complicated to tune. A TBI setup is probably the best, but throttle body injection is very complicated to set up and tune. Crazy expensive too.