Oh, no question about it.
The only people in the DCU dumber than Hal are his brothers.
Scipio is wrong. There is at least one other person in the DCU dumber than Hal Jordan.
Take the Green Lantern/Green Arrow
A reader who knows the characters understands that Hal can afford to take this trip. He lives alone, is a traveling salesman (who used to be a pilot, who used to be an insurance investigator...etc... Hal's jobs vary with his girlfriends, but that's another post entirely), has no one depending one him -- he can just pack up and leave. Ollie, on the other hand, has a young sidekick -- Roy Harper, also known as Speedy (and no, I have no idea why they named the archer kid Speedy and the superfast kid Kid Flash) -- that he up and leaves for this trip. The boy appears to be in his teens, and I see no evidence that he had any supervision whatsoever while Ollie was gone.
After the two adults get back, they run into Roy while investigating drugs and assume he's on the same track as them. He even rescues them after they've been knocked out and given drugs in an attempt to frame them.
The experience of being high leaves Hal asking why anyone would voluntarily undergo it. Roy gives him an eloquent, tear-jerking, and fucking transparent answer.
Now, most of us who've read DC comics know what he means already, so I may be wrong about how obvious it is. But I'd be willing to lay down my own hard-earned money that the majority of people who see that panel and have no knowledge whatsoever about the DC Universe other than the fact that the blonde bearded idiot and the redheaded kid have a hero-sidekick relationship will be able to know exactly what he's talking about.
But does Ollie?
In fact, he comes home and walks in on Roy in the act of shooting up and is absolutely shocked.
Does Hal? Well, it takes him a while, but he actually gets it.
The proof is in the panels, ladies and gentlemen. Green Lantern is seriously the smarter member of the team.