Only 3? Damn, that's difficult.
I can see myself buying a gen Panerai 113 sometime within the next couple of years, so that would be one. A decent rep Fiddy would make two. I'd have a hard time giving up my PAM111, but I'd have to have something different for a third watch - the problem is choosing just one as there's far too many to choose from. For today I'll choose a Rolex DeepSea, but ask me again tomorrow and you'll get a different answer...