I'm personally getting Madden 25, Assassin's Creed 4, and then Killzone Shadow fall. I might get a NBA game, I don't know yet. I already paid the $10 for my PS4 Battlefield 4, so I'll have that at launch as well. Maybe Call of Duty Ghosts? I don't know on that one yet, either.

If I were you, I'd roll with Knack as a definite rental (I think you'd be highly disappointed if you spent $60 on it). If you need another 3, how about Assassin's Creed 4, NBA, and then Madden to trophy whore?

Don't forget that you're going to be bombarded with games at launch because of all the free ones you get with Plus.