Realogy is the best play on the improving housing market because it is leveraged operationally and financially to existing home sales, said Martin Sass, CEO of M.D. Sass. Sass added that Realogy generates a substantial amount of free cash flow which it is using to pay down debt and will eventually use to buy back shares. He is also bullish on NorthStar Realty Finance, saying the company will benefit from its major healthcare acquisitions this year. Finally, Sass said he is sticking with shares of American Airlines despite its huge stock gains so far this year because the airline has streamlined its operations.