I know that the current Back to the Future comic book series features backstories and alternate stuff not shown in the movies (I've recently obtained the first two trade paperbacks, both are great). I'd like to see a series of comics showing how Biff was like between the time George knocked him out and 1985, in the timelines with and without the Sports Almanac. Maybe show if he was indeed scared of George at first, or if he struggled to bully others, maybe leading to him starting his auto detailing business and being a friend/customer to George McFly. And one detailing him after the punch, him no longer bullying George, what lead to him betting for the first time, showing him starting his ruling the town and what lead to him murdering George (I've read it was because George was going to protest his policies, but I wonder if he had wanted to kill George before that, for finally being able to stand up to him), and what his marriage proposal to Lorraine was like. I'd also like to see a comic showing Biff and George's relationship between 1955 and 1985 before Marty went back in time (one thing I'm really curious about is whether he tried to stop the wedding between George and Lorraine in the timeline where he was still able to dominate George).