Take DBD::CSV. (Please. *rim shot*) It impresses me greatly that I'm going to be able to work out simple SQL on DBD::CSV, and then, essentially just by changing my use DBD::CSV; to use DBD::MySQL; , I'll be able to use roughly the same syntax with MySQL.
I realize that this is the goal of modular code -- to be able to use as much of one thing in another, and to provide standardized syntax as much as possible for things that should have standardized syntax. I further realize that it didn't happen all by itself; it was the effort of other people that allows such neat, easy tricks.
I can't help it. I think it's really, really slick.