Warren Buffett should consider buying AutoNation (AN) to add to his portfolio of companies, according to Mario Gabelli, Chairman and CEO of GAMCO Investors and a Berkshire Hathaway (BRK.A) shareholder. Gabelli thinks AutoNation would make sense for Buffett because it is well-run company and it generates cash flow, and he would be able to make money financing car loans. It would allow Berkshire Hathaway 'to get bigger quicker.' Reflecting back on Buffett's fifty years as CEO of Berkshire Hathaway, Gabelli says he doesn't think there is anything Buffett should have done differently. For those who criticize Buffett for not paying a dividend, or for not buying tech stocks, or for holding onto some stocks for too long, Gabelli says 'if Warren Buffett were walking on water, people would criticize him for not being able to swim.' In terms of his own portfolio, Gabelli says in the current market environment a value investor has to be more selective. Gabelli is buying Ryman Hospitality Properties (RHP), which he thinks will produce good returns over the next three years. Gabelli also thinks Comcast (CMCSA) should buy Cablevision (CVC) as well as cable assets in Europe and Latin America, now that the deal with Time Warner (TWC) is off. Gabelli is also a fan of content companies Sony (SNE) and Viacom (VIA.B). He spoke with TheStreet's Rhonda Schaffler in Omaha, Nebraska ahead of the Berkshire Hathaway annual meeting.