For bowlers, I would have to say Akram. Warne was only really good between 93-97, and his failures against India have been discussed before. Waqar had his peak between 90-94 but was nowhere near good for the rest of the decade. That leaves Donald, Ambrose and Akram for true contenders.
There isn't much to choose between them, but I think Donald lags behind compared to Ambrose and Akram in making his mark against Australia. Between Akram and Ambrose, I would go for Akram for a few reasons. First, he was successful in the subcontinent in the decade, whereas Ambrose never played in India, had a poor series in Pakistan and a single test against an average Sri Lankan side. Second, and this is pure speculation, but I would argue that the majority of his peers would rate Akram better during this time, simply for being more versatile and awkward a proposition to face.