Milo Hamilton last broadcast Cubs games in 1984, so you'd likely have to be in your early 40s to have any significant memory of him as a Cubs voice. He broadcast for several teams, most significantly the Houston Astros, where he was the primary radio voice of the team from 1987 through 2012.
Hamilton passed away Thursday, aged 88. Major League Baseball Commissioner Rob Manfred issued this statement on Hamilton's passing:
"During his 60 years covering our game, Milo became one of the National Pastime’s most distinguished announcers, serving seven different Major League Clubs. He chronicled some of our game’s most historic moments during the era of Hank Aaron, Stan Musial and Ernie Banks. As ‘The Voice of the Astros’ since 1985, he ushered into the homes of fans Houston’s first World Series appearance, the Hall of Fame careers of Nolan Ryan and Craig Biggio, and countless other memories. "I enjoyed spending time with Milo during my trip to Houston earlier in this resurgent season for the Astros, and it was a pleasure to correspond with him in recent months. On behalf of Major League Baseball, I extend my deepest condolences to Milo’s family, friends, admirers throughout the game and to all Astros fans."
Hamilton first worked for the Cubs calling games on radio from 1955 through 1957. He came to the Cubs from St. Louis, where he'd worked one year calling Cardinals broadcasts with Harry Caray and Jack Buck. Reports at the time indicated Cardinals management wanted to make room for Joe Garagiola on their broadcasts, so Hamilton was let go.
The same thing happened to him in Chicago in 1958, when Cubs management wanted Lou Boudreau on the radio broadcasts, so Hamilton was out. Three years later he joined the White Sox radio team, leaving in 1966 to become the Braves' principal radio announcer. There, he called Hank Aaron's 715th home run:
He later broadcast in Pittsburgh before returning to the Cubs in 1980. He'd apparently been promised he would succeed Jack Brickhouse as the Cubs' main TV announcer after Brickhouse retired after the 1981 season, according to Curt Smith's book "Voices of Summer." But when Harry Caray became available after the White Sox dumped him following the 1981 season, new Cubs owners Tribune Co. jumped to hire him, relegating Hamilton to a subsidiary role behind Caray. Smith's book says that Hamilton blamed Caray for this as well as his departure from St. Louis years earlier.
In an article like this one, usually one hesitates to write anything negative about the person who's just passed away. But I think an obituary of Hamilton needs to mention his apparent lifelong disdain for Caray, noted in this 2006 Tribune article:
Mild-mannered Dutchie Caray decided Monday to break her silence regarding the vindictive personal attacks on her late husband--Hall of Fame broadcaster Harry Caray--which are included in a new book by Milo Hamilton. In the book "Making Airwaves," Hamilton refers to Caray as "a miserable human being." "That hurts," Dutchie Caray said. "All I really want to say is, I don't think Milo has shown any class at all. It is probably just to sell books. I hope nobody buys the book. "I was really, really disappointed in Milo. After 25 years to bring up these things ... and Harry has been dead eight years."
Hamilton left Chicago after 1984 and went on to a career in Houston that got him the Frick Award from the Baseball Hall of Fame in 1992, as well as being able to call several playoff seasons for the Astros and one World Series in 2005, and he was well-loved by Astros fans, as noted in Manfred's statement. Hamilton had a wide and varied broadcasting career that lasted six decades. For that, he should be well remembered.