What an interesting thread to read! My wife is similarly tricky in that she absolutely does NOT (and in my case it's not the usual Trick..she really doesn't) want me to spend money on expensive flowers, clothes she hasn't picked out herself, or jewelry. Frankly she hates restaurants (the waiting...patience isn't her strong suit) and a restaurant would be the last thing she'd want, although I love them.
I also take the position that we should both enjoy whatever we do for our anniversary and in the last couple years I've had success in planning things to DO - not surprises as she hates those too (difficult!).
One time we went to see a ballet, another time we took a small trip together. Pre-planned, no surprises, but it was "for" our anniversary (etc).
Seems to work well.