That's a rough one too. Any time we are at Target or some such and she is like "hold on I need to get (so-n-so) a (insert event) card." I immediately want to put a gun in my mouth.
The worst is when she finally gets it down to two and asks my opinion. I quickly point to one then she immediately starts telling me why the other one is better. So I say OK get the other one then. "But this one is good because..."