Coins and cards. Think I have a Nolan Ryan allstar card worth about $3 and a penny from like 1909 worth like $1....and some buffalo nickels and susan b anthonys that are worth face value. Not doing very good.

HO scale trains....25 engines and 250 cars. even have a layout to run them on.

Very cool GrasshopperG.
I also have a few watches
I find pool noodle and cast net containers very handy.

Rocks. From as long as I can remember the morning of a fishing tournament I would always search for a rock as a Good Luck piece for the day and would bring it home. Some held some significance as being a winning rock with extra Good Luck if I did real good in the tournament. Then it got me to hunting rocks. Then I bought a tumbler and started polishing rocks and still do that and put them in my wife's potted plants for decoration and even make some decorative displays using Cacti and Succulents.
I am about to venture into buying a wet tile saw and start cutting some of the rocks open and polishing. Some rocks inside are like looking into another world with some of the awesome looking bands and colors and fossils in them.

Waterford crystal bar ware.
Single Malt Scotch

Antique / old Case knives.

I've got close to 1000 vinyls, 1500 CDs, a bunch of music posters with lots of Armadillo WHQ posters, the exit sign from the Armadillo (Adios!), a box full of ticket stubs from concerts, tubs of shirts from concerts, a gun safe full of coins and fossils galore.

I visited the Waterford factory. The history and process and just flat amazing

Not my collection, I am merely the curator. My employer collects mod 94 Winchesters, old cowboy revolvers, spurs, and saddles

I Been Saving every single Bottle Cap I've Drank for the last 10 years

Wanted too make a bottle cap table, just haven't got too the Making the Table Part!

I collect the skulls of my enemies, and drink wine from them.
If the UN decides to start coming for Americans because of social media posts that are deemed offensive, I will begin collecting robin egg blue helmets with a hole in the forehead area.

We do the same

WOW!

Replied sir.