I was going to say IPA or IIPA, but, for the rest of my life? A little lower alchohol means I could drink more without passing out when I was older. So a good, hop bursted and dry hopped American Pale Ale!
I know it's going to be the popular answer, but I'm going with IPA as well. It's crisp and refreshing enough to be a good summer beer, but hearty and warming enough to also be a good winter beer. Perfect for all seasons, really!