Could you be more vague, please?
A quick search of the database--which you could've done yourself, by the way--shows three AMVs with
GTA3 as their source.
(deep breath)
I don't know why I am so patient with queries such as this, but here are the links to those individual videos:
Flying off in a Blaze of Glory
Tanner Strikes Back
LCPD
There are also a couple of shorts that use commercials from
GTA3 but I'm not going to do everything here.