Weirdly enough it seems a rarely discussed topic, unless I’m looking in all the wrong places, thought it would stir some debate.
Flash and Jaedong were hall of famers in Brood War and had results in SC2 that would be considered pretty damn good for players not called Flash and Jaedong
Rain had a lot of hype around him as being one of the coming men in Brood War before the end of the Kespa era and never really got to fulfil that for reasons outside his control, switched to SC2 where he became the best Protoss if not the best overall player for periods, then switched back where he’s had fantastic results in the post-Kespa Brood War scene. Soulkey was in a vaguely similar boat to my knowledge.
Those are a few names that spring to mind given my relatively limited knowledge of BW talent.