Sean William Scott or Chris Pratt would bother be good choices. I think Scott might be a better fit of you think of him from American Pie as Stifler, and that same personality would mesh well with the “selfish ad boy” side of Gold when he’s promoting various products. Just watched Jurassic Park Fallen Kingdom, and Pratt seemed like he’d be a decent fit too.
Who do you think would be a good Booster Gold character?
A while ago, I created a similar thread. And, I said… CHRIS Pratt. Dude is freaking awesome.
I still say that the Adam Strange part on Krypton was originally written for Booster Gold, maybe because in my head, the actor that plays Adam (Shaun Sipos) would be a great Booster.
If he were a little younger, I’d say Nathan Fillion. He’s probably a little old now, though.
Sean William Scott would make a good fit – it would also feel especially meta since both actor and character had impressive peaks in their careers and then they both sort of fell out of the limelight.
I’m going to say Bradley Cooper just because I want him in any DC role 
If this was 2003 or 2004, I’d say Jacob Pitts. I remember watching Eurotrip where he and Scott Mechlowicz played best friends. If you watch that, you could totally see them as Booster and Beetle!