My downfall is company. If I'm with a good crowd, I love the craic - years of travelling with big crews meant basically a party most nights, if you were up to it. I can't do it more than once in a while these days, as the recovery period is too debilitating! But on my own, even with a very good bottle of wine, I usually get bored with it and give up and have a coffee. Occasionally, I'll be in the mood for lots of music and a whole bottle on my own - and those evenings are fun - but they are few and far between.
I rather like alcohol, and my relationship with it is far less unhealthy than some. But I may well do the 'dry January' thing, just to say I did it.