This is not my original idea -- I read it a few years ago in Nursing Management (I think). But I thought it was such a good idea, I'll pass it along here.
Instead of GIVING the nurses some little trinket (it's always something you really don't need, a cup, a bag, a pen, etc.) this hospital picked a charity that the NURSES CONTRIBUTED TO!!
They happened to select a women's shelter. Each nurse and unit put together the sorts of supplies that women need -- toiletries, cosmetics, pantihose, sox, pajamas, etc. and on Flo's birthday (the focus of Nurses' Week) they sent a delegation over to the shelter with cartons of supplies at their way of celebrating the week!!
I thought it made a great statement about the generosity of nurses. I always wished I could have been working at that facility when they made that loving gesture.
No matter what you buy for your nurses (cookies, dinner, trinkets, etc.) it will not have anywhere near the impact as what you invite them to DO as a demonstration of all that nursing is and can be in our communities!
Good luck as you make your plans!