I've been happy with a Weaver Multi Slot base. Which one you get depends on the rifle configuration: long action, short action, Accustock, Accutrigger. I like it because it can be used for any type of sight that can be rail mounted with quick release of the scope. The size of the scopes's objective end will make a difference on the rings, too.
Here's a photo of the base on a Savage 16FCSS, .223, short action, Accustock, Accutrigger. The scope is Weaver 800360 First Focal Plane Tactical 4-20x50 Mil-Dot. The rings are Weaver 6-hole 30mm Tactical.