USA GEAR Protective Hard Shell Travel Case for Select GARMIN GPS Navigator Units - Includes Accessory Bag
I have bought two of these cases, one for myself and one as a gift.  I like a hard shell design so that the contents are fully protected.  I've not had any issues with fitting accessories and there are several compartments to keep everything separate and not ending up with all the cords as spaghetti.  I would certainly recommend this to others.