The best Bradley transfer in would be a close call between Les and Steve Kuberski. Kuberski transferred from Illinois after the slush fund scandal. He was first team all MVC in 1969 and played 9 years in the NBA, scoring 3,114 points and winning two titles with the Celtics.
http://en.wikipedia.org/wiki/Steve_KuberskiStuckey (Drake) and Mike Williams (Cincinnati) would be in the next tier.
Future NBA all star Danny Granger would be the best transfer out obviously. Joah Tucker probably deserves a mention too though. He left with Granger and went to UW-Milwaukee where he was Horizon POY and led them to their own Sweet 16 in 2005. Let's hope we don't have to add Cunningham to this list, ugh.