hmm... I dunno. all the cards I've gotten from friends and family over the years are really special.
all the Christmas presents I've gotten from my one friend are super special...
my Pokemon Silver cartridge is one of my most prized possessions for sure.
I have a lot of stuff that's pretty special to me, really. ~__~
my cello (it's helllllla old, mid-1800s i think? maybe earlier)
my gran's wedding ring, i don't know if i'll ever get married but it's been in my family for generations (her gran left it to her when she died and she left it to me) and i treasure it haha
It would definitely my dog Flair (She's my profile photo ) and my Games + Merchandise collection, it is not too big but big enough to prevent you from getting bored anytime!
My most prized possessions are not really physical items, they are certain people/animals that are in my life. Based on that I suppose my phone or laptop would be my most prized possessions as they're my primary way of keeping in touch with those people when I can't see them in person.