You can readily see from the responses that there are as many opinions as there are knives. It's likely your friend's needs and wants have changed over time; that, along with evolving technology and designs, makes selection a moving target.

Ron summed it up well: "A good knife is a personal thing, really hard to pick for someone else."

It's not as gratifying as actually presenting your friend with a knife you went to great pains to select, but have you considered a gift certificate from a knife dealer?
Here's one such possibility (not necessarily an endorsement, just an example). Or, if you do purchase a knife, make sure the dealer has a reasonable exchange/return policy just in case. And pick a retailer who carries a wide selection of good brands.