Hmmm...I cannot, in good faith, call a team where the core has one a championship a choker. If anything it shows how hard it is to win a championship and how many variables play into a short series when the teams are generally really close in talent. Astros may debatably have more talent on their roster overall than the Yanks, Nats, and Dodgers for example but it really isn't that much of a difference in a short series. Saying that, I'd still rather be the favorites.
The core four for the Yankees (Jeter, Rivera, Posada, Pettite) really aren't chokers but after 2000, it took them another nine seasons to win the WS again.