I buy stainless steel cleaner wipes. They're in a pop-up container like baby wipes so very convenient. They clean gunk off as well as fingerprints (and dog nose-prints!) so if you have a DH like mine that cooks "explosively" it's a one-step deal to remove the tomato sauce and all the smudges in one swipe, LOL. We've had this 'fridge for 4-1/2 years and I'm still on my first container.
If I see JUST fingerprints, I'll quickly buff it with a paper towel (or my sleeve if I'm being lazy) and that takes care of it handily. I think the wipes leave a coating behind that makes it easier to wipe off fingerprints in between true cleanings.