Noone beats Imran when it comes to grace.
Imran khan has the best action i have ever seen specially his jump and landing were all smoth and classic and now a days yes its Allan Donald his action is also a classic to watch specially when he is bowling against the wind 
IMRAN KHAN 
Allan Donald will be from my side as a Non-Pakistani
Yes imran action was best.
Kapils and Walsh's action was smoothest though.
lol @ some of the replies
okay waqar younus has a great bowling action and I think he is simply one of the best fast bowlers to come out of pakistan cricket scene. But it is more a matter of personal opinions - nothing against anyone :)
I liked Imran Khan's runup and bowling style . The classic fast bowler delivery - with the left arm raised and the left eye judging the batsman for that last second decision about where to pitch the ball :)
From outside pakistan I think Dennis Lilly was pretty good . Quite a devastating bowler in those times - those ashes series were really a treat to watch.
Imrans action was THE best ever, don’t remind me man just don’t kya din thay wo… :k: :k: :k: