What's the best file recovery software?

[Cary]

Just got a call from my 83 year old father - he deleted "a bunch of stuff" from his Mac - "cleaning up," he says. He just realized that he somehow deleted all the family pictures off the external hard drive.

Best of all, this was 4 days ago.

Now he wants me to see if I can recover any of it.

Here's my question: What's the best Mac file recovery software these day? Extra points for free or cheap.

Thanks,

Cary