The biggest name in aftermarket base pins is Belt Mountain. Most of the people selling aftermarket base pins (incl. Brownells, Qualitas) are re-selling Belt Mountain stuff.
Most Belt Mountain variants have a small set screw through the head, that allows you to lock it firmly down so that it cannot pop loose under major recoil. Tightening that is recommended if you're going to shoot hot .44Mag, .45LC+P or custom chamberings like the Linebaugh calibers, .454Casull, etc.
Some Belt Mountain pins have nicer heads that are easier to get a grip on than the Ruger part.
Finally, they sell a "Sheriff's model" base pin that has an abnormally short head, which lengthens the ejector rod travel. Ruger has a base pin for their factory "Sheriff's model" 3.5" barrel guns that has an even shorter head, but it doesn't have the set screw - the Belt Mountain short-head pin still has a set screw.
That particular pin, the Belt Mountain short-head with set screw, is of particular interest to me. Now that I've *finally* got money coming in soon, a stainless 4.6" .44Mag Vaquero is in my future. Only reason for .44Mag is flexibility in ammo selection and flatter long-range trajectories. It'll give up a bit of peak power over .45LC but...that's OK.