Who is it? The only one's I can think off the top of my heard are John Mugabi,Boza-Edward and Ayub Kalule
Kassim the Dream Ouma was really exciting for a couple of years and looked like a future star until Karmazin dominated him. A year or so later he challenged Jermaine Taylor with the middleweight belt but was simply too small at 160 and was never really same after that loss. I'm going to go with Boza-Edward for the top spot.
With all apologies to The Beast, who's career was shortened by a prime Hagler, I will have to go with Boza-Edwards.