When you say "Hal is the greatest," you're also saying, "These other ones aren't as good." Yet you're trying to make the others sell comics! That ain't gonna work, now or ever.
But besides "Hal is the greatest," I think the other classic example of saying something about a character and not backing it up is in claiming that the Martian Manhunter is "the soul of the Justice League." Really, what does that mean? It's just an advertising jingle for a product that people aren't much interested in.