For what purpose?
I've got a Leupold 3-9x40 (can't remember if it's a Rifleman or VX1) on mine and it works for prairie dogs and jackrabbits at reasonable ranges. It'd also work for fox and bobcats in all but the thickest brush. I'm pretty fond of the 3-9 range for most purposes, so that's what I'd recommend. I usually recommend Leupold because their scopes are trim
and light, have good glass for the price, and are made in the US.