I was going to say Nick Weatherspoon. In his 3 years he averaged 20.9 ppg (before the 3pt) and 11.3 rbs/gm. These are the all-time record for career per game averages for both scoring and rebounds for the Illini. His senior year was 25.0 and 12.3. For comparison, Kofi's career numbers were 17.2 and 9.6 with his best and last year being 20.9 and 10.6.
This was during my youth , but I do remember the teams during the early 1970s were frustrating to watch (and not just because the TV was in black and white and it looked like they were playing in a snowstorm) with Weatherspoon being almost the entire show. Since Weatherspoon's teams had marginal records, he would have probably been more revered if we had been more competitive during that time. Of course he may not have had those numbers on a better team.