For fun you might want to go by the Golden Nugget and drool over the display of the gold nugget i.e. the Hand of Faith
Likewise, for the novelty of it you might also check out the "Gold to Go" vending machine they have on the floor where you can buy bullion gold bars and coins. The premiums they charge are outrageous but the little bars have a Golden Nugget hologram on the back or at least they use to, which makes for a neat keepsake.
As far as silver there are no "Silver Strike" machines anymore that give out real silver. All the ones now i.e. at the El Cortz, Four Queens, Mirage, and Sam's Town are all clad crap tokens and not worth messing with. Also note that there are some counterfeit Silver Strike tokens from China floating around so beware.