I've been good about sticking to previous resolutions.
For 1997, I resolved to understand personal finance better, in particular, where I was spending money. So I began to track with Quicken, switched over to Money, and have kept that up.
For 1998, I resolved to get more exercise. So I started running in the spring, and have kept that up, and even branched out into triathlon.
One resolution I've been bad about keeping is to cook more often. Part of this is the simple fact it is a drag to cook for one person. I'd either wind up with leftovers for three more meals, or have to scale down every recipe. So I wind up eating out, eating with friends, or getting frozen meals at the store.
I'm going to try this resolution again. Maybe I can stick to it this time!