I still say play the ponies. It's a great vice because it's not really a vice if you learn the math and don't get greedy. You'll actually make money (albeit not a lot of money) most of the time if you approach it that way.
But it looks very much like a vice because most people will view you as a degenerate gambler; so you get the appearance benefits of having a vice while secretly making a few bucks in the process most of the time.
For the full effect, however, you have to go to the track to gamble at least some of the time. OTB may be a more efficient way to make money at the track (and illegal bookies even more so); but perfecting the degenerate gambler persona requires at least an occasional day at the track.
That's okay, though, because a day at the track is almost always a good day. It's the cheapest professional spectator sport around -- as long as you keep doing the math and don't get greedy. With discipline, you'll come out ahead more days than not.
Rich