I collect coins for special memories or events. Examples are Olympic and sports coins, or places I have been. I usually get a mint set from a country I have visited in that year.
I also collect special issues for famous places I have visited in prior years. I like silver or proof coins so they have some lasting value in addition to the memories they provide. I also have common coins I have left over in change from various travels to Europe and other countries. These are not of numismatic value but are interesting to me as souvenirs.