Winsome

Well! This is very tough question to rate them we've to choose best, better and good bowler.
If we look at Imran he was a player not only a bowler but also batsman and he brought passion in cricket. His average at peak was just under 15. None can touch at their time of peak to his avg. He had the ability to change the situation of game at any time when he wished. Waqar's avg at his peak was under 21 but is strike rate was marvelous 38 none can touch this strike rate. He was speedstar before Shoaib's arrival. He was the master of swing and reverse swing yorker. Wasim's avg at his peak was under 20. He was the bowler who lifted Fast bowling after Lillee, Marshal and Imran. His run was short but his action was very excellent and versatile. He could bowl at any state of game. His achievement in WC 92 cannot be forgotten.
Wasim picked more wickets in test and Odi but in my point of view Imran and Waqar superior than Wasim.
Mine sequence would be
Imran > Waqar > Wasim.

I've select every bowler's peak 6 years to see their performance an results are;

10. Ambrose
189 wkts at an avg of 20.24 with a s.r of 50.8 (1993-1998).
9. Lillee
203 wkts at an avg of 22.17 with a s.r of 45.9 (76-81)

8. Holding
151 wkts at an avg of 21.61 with a s.r 45.9 (81-86)
7. McGrath
286 wkts at an avg of 20.5 with a S/R of 48.1 from 1995 to 2000.
6. Wasim Akram
195 wkts at an avg of 19.87 with a strike rate of 46.4 (1990-95).
5. Hadlee
222 wkts at an avg of 18.76 with a s.r of 46.1 (83-88).
4. Donald
233 wkts at an avg of 19.88
with a s.r of 43.1 (95-00).
3. Marshal
238 wkts at an avg of 18.90 with s.r of 43.1
2. Imran Khan
154 wkts wkts at an avg of 14.85 with a s.r of 40.9 (81-86)
1. Waqar Younus
194 wkts at an avg of 20.02 with a s.r of 38.0 (90-95)

The strike rate of Waqar and the average of Imran was unmatchable at their time of peak.

I've select every bowler's peak 6 years to see their performance an results are;

10. Ambrose
189 wkts at an avg of 20.24 with a s.r of 50.8 (1993-1998).
9. Lillee
203 wkts at an avg of 22.17 with a s.r of 45.9 (76-81)

8. Holding
151 wkts at an avg of 21.61 with a s.r 45.9 (81-86)
7. McGrath
286 wkts at an avg of 20.5 with a S/R of 48.1 from 1995 to 2000.
6. Wasim Akram
195 wkts at an avg of 19.87 with a strike rate of 46.4 (1990-95).
5. Hadlee
222 wkts at an avg of 18.76 with a s.r of 46.1 (83-88).
4. Donald
233 wkts at an avg of 19.88
with a s.r of 43.1 (95-00).
3. Marshal
238 wkts at an avg of 18.90 with s.r of 43.1
2. Imran Khan
154 wkts wkts at an avg of 14.85 with a s.r of 40.9 (81-86)
1. Waqar Younus
194 wkts at an avg of 20.02 with a s.r of 38.0 (90-95)

The strike rate of Waqar and the average of Imran was unmatchable at their time of peak.

Waqar and Imran are really greatest fast bowlers, as Waqar was the master of swing yorker noone could play his yorker, and Imran was the founder of reverse swing. Passion came in cricket with his arrival and gone with his departure, I cannot forget his match winning performance.
In last over Australia need just 3 runs and they have 3 wickets in hand, last over bowled by Imran and he the great man picked up all three wickets for just 1 run.
Noone can be compared to Imran even Waqar or Lillee.