all are university affiliated community programs, so if you want something really competitive like Pediatric Surgery, you need academic all the way. Of these 3, St. Luke's is the one that I would say is the best of the 3 from my research (as a MS4 myself, I don't know how much I actually know). Of the affiliations, it has the best (Lenox Hill is also columbia affiliated, but is definitely the bottom of the 3 in my opinion). I have heard good things of BI though, so either wouldn't be a horrible decision to interview at, but like I said, if you are going for competitive fellowship, think academic. See you on the trail (I have St. Luke's Dec 18th and BI Jan 22nd, turned down the Lenox Hill interview)