Here are some ideas to get us started:
I resolve to:
Lose 10% of my body weight by July. (Once you reach this one, figure 10% of your remaining weight and give yourself 4- 6 months to lose that. Keep going until you reach your goal weight.)
Introduce one new healthy recipe to my household a week. (Make sure to include things you know everyone will eat in this meal just in case someone hates it.)
Eat one more piece of fresh fruit daily.
Eat one vegetarian meal a week. (Great for meat eaters, as we tend to overlook the tastiness of non-meat meals.)
Add 15 sit-ups (jumping jacks, crunches, push-ups, what have you) to my weekly routine. (If you do them 3 times a week, you're only adding 5 per session. Once this becomes comfortable, add 15 more a week. Keep going until you're at a good maximum for you.)
Leave the last cup of coffee in the pot.
Cut out one cigarette a day. (Again, this can be an ongoing goal, cutting out one more a day as you stop missing the last one. Eventually you can quit altogether.)
Eat something for breakfast every day.
Try out one new exercise DVD a month. (Check the cheap bins at Target and WalMart; I've found some great ones there.)
Reward myself each time I reach a goal. (This can be literally anything. Buy yourself something for your hobby, rent a DVD that you've been wanting to watch, buy yourself a new top... Just make sure you do something to pat yourself on the back.)
These are just suggestions, but the idea is to set a goal that you're more likely to work toward and reach.
And my #1 New Year's resolution?
I resolve to follow my own advice.
Cross-posted; sorry if you see this more than twice.