During the trilogy we see 3 different versions of him. In the original timeline he was a wimp all his life, too scared to fight back. As such he was an easy target for bullies such as Biff Tannen, who bullied him unil 1985. George met his future wife, Lorraine Baines McFly in 1955 when her dad knocked him over with a car. She felt sorry for him, they fell in love, married, and had 3 kids: Dave, Linda and Marty.
Life for George changed in 1955, however, when his future son Marty accidentally interfered with his meeting Lorraine. Marty, under the alias "Calvin Klien", tried to get George and Lorraine together, but she had the hots for Marty, not George. Marty and George came up with a plan in which George would "rescue" Lorraine from Marty, but Biff interfered and George ended up really having to rescue Lorraine from Biff. George punched-out Biff and gained the confidence to do what he wanted. By 1985, he and Lorraine were happily married with the same 3 kids, and George was a science fiction author. His first novel, A Match Made In Space, was published in 1985, and in 1973 he won an award.
In another version of 1985, George was murdered by Biff in 1973. This Biff had received a sports almanac in 1955 from his 2015 self, and had thus become a millionaire. Biff murdered George and married Lorraine. Thankfully, Marty and Doc Brown put things right again and George is now a healthy, cool author.
George likes playing golf and tennis with his wife, and believes that if you put your mind to it, you can accomplish anything - advice told to him by Marty in 1955. He also has a very unique laugh. His favorite TV shows include Mystery Science Theater and The Honeymooners.