My students used to tell me that I looked like Richard Dreyfus, especially after Mr. Holland's Opus came out.
My last name is not Holland but some of the kids accidentally called me "Mr. Holland" for a couple of weeks. It was flattering to me but embarrassing to them, I'm afraid.
Moving to baseball, there was a player for the St. Louis Cardinals named Mark McGwire. He had auburn hair and a goatee (see picture below). I had a full beard at the time but decided to trim it back into the goatee like McGwire's, never really thinking I looked a lot like him. However, after I did it, a LOT of people started saying how much I looked like him. One day while I was at a Pirates/Cardinals game in Pittsburgh, I headed up to the concession area from my seat. (Note: I was wearing one of my Pirates T-shirts.) I bought a hot dog and was adding some ketchup to it (in Pittsburgh, that's a popular condiment for hot dogs--not just mustard). I saw him off to the side and became aware of the fact he was just staring at me. He was a middle-aged man who was completely drunk, standing there with a beer in one hand and a burger in the other, staring at me with his mouth and eyes opened wide.
He staggered over to me and said, "Do... do you know... who you LOOK like??? <urp>" I could see that everyone around had turned to listen to my drunken friend, so I simply nodded and said, "Yes... I'm his brother." He gasped loudly, raised his burger hand up to his mouth to cover it in shock, and said, again quite loudly, "HOLY MOTHER OF GOD!!!!!!!" There were about 40 of use laughing our butts off. :-)