AC hasn't made spark plugs in decades. Far as I know, they're bought-in from NGK. At least, some part numbers are NGKs with different markings, in an ACDelco box. I like NGK.
I was big on Autolites until they moved production to China.
My Trailblazer came with Iridium plugs. The originals lasted 160K miles, coming out at 90K--and they looked so perfect they went right back in, even though I'd already purchased a new set. I wouldn't put Iridium or Platinum plugs in a carbureted engine, or even a TBI. But for a port-injected OBD2 engine that doesn't have a history of oil consumption...sure.
Haven't bought a Champion plug in decades; I swore I'd never buy another Champion when I figured-out they had the most-brittle porcelain in the industry. Soft, fast-wearing electrodes, too.
Not real big on "gimmick" plugs, either. Splitfire, E3, the Bosch plugs with two or four ground electrodes...No, thank you.