Not exactly a New Year's Resolution, but I gave up alcohol while I was training for the marathon last year (4+ months!
) . It was hard for the first 6 weeks, especially as people would always be asking why I wasn't drinking and then trying to persuade me to just have one. It got a lot easier after that, and now I really can take it or leave it.
I think I've got a bit snobbier about what I'll drink since then, because I don't buy booze very often I feel justified in buying much nicer stuff when I do fancy it. I don't know how I managed to drink the Vodka With No Name from Tesco when I was a student 