I'm bored and really enjoyed seeing some high end Mausers in the other thread. So you define "nicest" and then show the top three of your collection.
Three "nicest" for what? Target shooting on a warm, dry day? Hunting in the rain or snow? Busting through brush or hunting the barren plains? Hunting from a stand or carrying for miles at a time up mountains and down? Prettiest or most functional?
Sold my prettiest rifle, a Ruger #1 in 280 Rem, because it was too pretty for my needs - a fair weather rifle and not one I wanted to get knocked around hunting elk. For "nicest", I go with "most functional". That would be a close race but a synthetic-stocked rifle that shoots great would be my choice.
My Ruger All Weather (stainless/synthetic) Hawkeye in 280 Rem would be the runner up. It can bang the 6" steel at 600 yards with ease, is relatively light weight and easy on the shoulder. It will easily put down anything I want to shoot, from varmints to elk.
The winner, though, would be my stainless Ruger MKII 30-06. It came in a laminate stock that I replaced with a Ruger "boat paddle". Like its siblings, a 300WM and 338WM, I've used it to shoot clay pigeons on the 600 yard berm. It is the one in the middle of the photo below. The 300WM is on the left, the 338WM on the right.