> sound like a silly question, but would this increase the collectibility of
> this game? Or in such cases would a programmer's autograph make more
sense?
It depends on what you're going for - personal interest or a monetary
investment.
If it is the former then you're good to go. Get the game signed by whomever
you want.
If it is the latter then a lead voice actor is probably just as good as a
lead programmer.
Personally I collect for myself and I shoot for getting the lead developer's
autograph. Whoever developed the concept of the game is the one that I
prefer to have sign. I also prefer to have the signature on the actual disc.
Others prefer to have the signature on the instruction booklet or front
insert.