I use the Air Spencer CS-X3 "Squash" scented air freshener - I've never had air fresheners in my car before, but I love this one. To me, it basically smells exactly like the original Ramune Japanese-brand soda.
This one comes in a little plastic cartridge that I keep in the storage slot next to the shifter, and everyone that had ridden in my car mentions liking it, or that it smells really good. I just changed out my cartridge the other day for a new one
