Wasim Akram - should have picked up more wickets especially in tests. Diabetes didnt help his cause.
Waqar - his back injury caused the world to lose potentially the best fast of all time.
Inzimam - didnt do justice to his talent. Weight issues, running between the wickets etc. Even Imran khan said Inzi under achieved.
Damien martyn - retired too early
Shane bond - due to injuries
Flintoff - retired too early, didnt make full use of his bowling talent.
Ashraful - lost his marbles, became corrupt
Umar akmal - lack of cricketing brain
Vinod Kambli - lack of cricketing brain
Ajit Agarkar - always had a soft spot for this guy. Thought he was more talented than what he achieved. For me, he is among the top 3 Indian pace bowlers ever in ODI cricket.
Stuart Mcgill - thanks to Shane warne.