It's Wasim clearly, but not by much. The lad who said Imran might have been better at his best has a right fine point. Imran in 1982 is scary. But it's Wasim. To be honest you could make an argument Waqar was better too. I'm not saying he is, but it would be a closer comparison. Waqar is underrated in that he has the best strike rate of any bowler in the modern era and it rivals SF Barnes. Yet he sprayed runs getting wickets, but getting wickets so fast means it doesn't matter.
Wasim's the most entertaining fast bowler ever for me.