Amazing how many people want to rename this car! I've heard the same idea from several friends who can't wait to pull off those G8 emblems, and now I'm seeing it in these posts. I agree it would be fun to put on something meaningful - but what?
What little consensus exists suggests it should not be alphanumeric - that it should return to a storied name with some history and brand recognition to it which evokes the earlier great years of the "Wide Track" era. Remember though, that at a wheelbase of 114.5" this is an intermediate car - not full-size . Full size cars traditionally have had a wheelbase longer than 116", so only the LWB WM-Zeta cars (2020 Chevrolet Impala? I hope I'm just kidding about the year) will qualify. For that reason I think you have to discard the names traditionally attached to LWB cars of the past including Torpedo, Chieftain, Streamliner, Executive, Catalina, Bonneville, and Grand Ville. Even if you don't buy the wheelbase argument - it just doesn't look like a Bonneville!
You are left with intermediate wheelbase names from the past - Tempest, LeMans, Phoenix, Grand Prix, Grand Am, and Ventura.
Finally, it hasn't helped the legacy of Pontiac that some of those names have been slapped on front-wheel drive cars in some cases and should be disqualified due to our immense suffering of recent years. This eliminates Grand Prix, Grand Am, and Phoenix.
I find Tempest sounds a little dated, and LeMans a little pretentious, so the winner for me is... VENTURA. It will be hard to find emblems at your local Pontiac dealer parts department though.