My favorites would have to be Newfoundland Gold coins and old U S Gold coins.I buy them every chance I get.so maybe it is an addiction.
Wheat pennies- I can't wait till the value of each penny goes up 1 or 2 cents and adds 600 dollars to my collection... Morgan and peace dollars.
BIG silver, as in crown-sized or larger, 40mm silver American Eagles, big 45mm Franklin Mint Caribbean $10 and $25 coins, 61mm Panamanian B./20 and, of course, 76mm ATB 5-ounce pucks!
I'm addicted to and love early gold......btw, none of these are mine. I still love 'em though. The 1822 is the most modern of the group and worth more than the other 3 put together.
I have an addiction...but not a problem...yet for any coin that catches my eye. It could be an ancient classic or a new proof set if it looks nice enough to me.