Bad habits?
I've broken my worst one: biting my nails. I just woke up one morning about thirty years ago, decided it was a nasty habit, and have never done it again.
I've never smoked, and I only drink lightly, so that's not a problem.
I suppose I need to break the habit of buying so many DVDs as I have more now than I'll probably ever get to watch more than a few times, but there always seem to be favorites that still await release, and when they come out, I can't help myself.