Proof Coins Are Beautiful
The bulk of my silver stack is in constitutional/junk, bars, and government bullion coins (in that order). But every once in while, I get some proofs/commemorative/collectible/numismatic coins. The premiums are pretty hefty on these, so that's why they just are 2% of my stack. But buying a proof once in a while won't hurt
Looking at them with a loupe, you can really appreciate the superior dies, polishing, frosting/mirror finishing, and craftsmanship that took place. They are like mini works of art. In addition to this, it's always nice to have a nice case/box, with a certificate of authentication along with it.