Here are a few other music ones -
John Popper of Blues Traveler, is a big tactical guy.
------------- Not collectors, but an interest in specific knives -
Keith Richards liked Okapis, and other ring pulls.
Steve Jones of the Sex Pistols carried an Endura.
Dee Dee Ramone had an affection for the 007 knife, because it was a big, cheap, quick folder. He'd even mention them to other punk rockers like Sid Vicious who used a similar type during the whole "Sid and Nancy" thing.
Various members of the Cro-Mags liked the 007 for much the same reasons as Ramone.
K.C. Armstrong, who was a member of the Howard Stern crew for a bit, liked Spydercos. I think he gave Stern one, as Stern mentioned he got one as a gift, and it was a neat little thing.
Edit -
Ice T and Sir Mix a Lot also liked fantasy knives and swords.