Here is the list
I got this from the Lee Sinins Complete Baseball Encyclopedia. The age column shows their age as of June 30. So if a guy turned 25 on July 1, his age for that season is listed at 24. But all of these guys turned 25 after the season in question. They are all pretty much Hall of Famers or guys who put up Hall of Fame type numbers, except for Sizemore and Trosky.
But even Trosky was very good. Through age 27, he is 124th in career WAR among position players. If he had finished with that rank for his whole career, he would be a borderline case. He only played 312 games after the age of 27. His SABR bio says he suffered from very bad headaches starting around that time. He also finished in the top 7 in OPS+ 4 times.
Sizemore had 53 2Bs, 11 2Bs, 28 HRs.
Through age 25, he was 48th in career WAR among
position players. He had 4 straight years in the top 10 including a number
1. Maybe he was headed for a Hall of Fame career before injuries.
And here all the guys that had from 85-89 under age 25 (I did not check to see if they turned 25 in the season in question so a few of them might have made the cutoff after their 25th birthday). It is also a pretty impressive list.