Cool in the sense of collected, not brash like Naruto, who obviously has a lot of self pride.

Sasuke does not "Suck". He's very good at what he does. He lost the fights he lost due to bad match-ups.

Orochimaru? The Third could barely handle him, let alone a Genin. This fight has no place here.

Gaara? He didn't lose against him, he'd be dead if he had. There's no possible way he could have fought a 50 foot tall raccoon, nor could 99% of Konoha. Naruto stepped in and took the fight over when Sasuke had over-spent himself in what he thought was a surefire way to end the fight. And Naruto could only do it cause he could summon Gamabunta, who did most of the fighting anyway.

Haku? He got knocked out cause he was protecting Naruto. He was beginning to decipher Haku's movements more and more (If not cause of his Sharingan, then because Haku was running low on Chakra after so long). So there is a chance that eventually, after a long drawn-out battle to see who had the most stamina, Sasuke could have won if he hadn't protected Naruto.

And anyway, Naruto is the character that is supposed to get the starlight. As good and cool as Sasuke is, he's a supporting character, so he should have less victories, or atleast less spectacular ones, thatn Naruto.