Depends what you are shooting, and what you like really. I like 100 because I try to stay standard for everything I shoot. BUT if you will only be taking long shots, something different may work better for you.
I am wanting to shoot between 1 - 1 1/2 miles. The scope is a Leupold Mark IV 16x40 with a tactical reticle. It has 140 total vertical moa (the reason I bought it) and I believe the scope base is 20 moa.