I myself just saw a little bit of Lille, not much, and not in his prime anyway. So I am not a good person to judge probably.
But among the greats there isnt much really, the wkts, averages etc are all very close. S/R is not the most important stats in tests, but still Waqar's s/r does distance him from the rest.
In ability, its really difficult to think that anyone could have more ability than Wasim. But he didnt do complete justice to his talent, especially his lenght was too short generally.
If we disregard the stats etc, I'd say if I were picking a team, I would pick Amborse higher than Marshall. And Donald would be high. Whatever I have seen and heard of olding and Roberts (seen very little in Roberts' case), I would like that tandem over any other, even Wasim and Waqar.
Imran's perfomrance in 1982-83 against India is probably the best I have seen any fast bowler bowl in a complete series, considering the quality of opposition and bowling conditions.