Larry Mullen Jr. has been a PAISTE cymbal endorser for 20+ years. He's been playing PAISTE brand cymbals exclusively
since (at least) the WAR tour, if not a bit sooner.
Larry used mainly PAISTE "Rude" model cymbals, during the WAR and UNFORGETTABLE FIRE period.
Larry began using the PAISTE "Signature" line upon their conception in the late 1980's-early 1990's.
I do remember seeing some pictures of Larry playing some Zildjian cymbals, early in his career. Larry can be seen
playing Zildjians in a recent (May 2008) U2.com post of Larry in the studio.