Apollo wins. He's stated to be Majestic Class, which means he can lift hundreds of thousands of tons. I don't think Spartan has been in the ballpark of Mr. Majestic without having the Void inside of him. From what I've heard about Invincible, he's the first to go since his strength is apparently a few hundred tons. Spartan and Superboy are probably close to each other in strength and while they're capable of causing trouble, Apollo would come out on top.