Pepsi Max has used Snoop Dogg in their most recent campaign.
But it's not just an appearance... in true Pepsi style, Snoop performs the 'jingle' within the spot.
My favourite thing about Pepsi endorsement ads featuring musicians are that they have nearly always used the artist's own music, rather than just the artist's image. The music will then have the lyrics tailored for the campaign (Michael Jackson's "Billie Jean" was turned into "You're the Pepsi generation, guzzle down and taste the thrill of the day, and feel the Pepsi way"). It's cheesy, but it works.
Check it out here:
And a few other Pepsi ads featuring musicians below...
Bob Dylan & Will.i.am
David Bowie & Tina Turner
Rod Steward & Tine Turner
Mary J Blige
Justin Timberlake (this one was for a Pepsi competition, rather than just being a brand spot... so it doesn't quite match the same Pepsi formula. It does use JT's music, but doesn't really incorporate it lyrically in the same way)