]Who makes the best laptops is entirely subjective[/B], but that doesn't change the fact Asus makes some of the better machines out there. The Zenbook actually outpace the MBAs in some regards (now that they've fixed their janky touchpads). I'd consider them some of the best ultrabooks around.
Their G series laptops run cool, have tons of power, and are solidly built. You want power in a (relatively) thin package, they're the ones to get.
They even made some of the better netbooks back during their heyday.
Asus is hardly what I'd consider a budget brand. Though I will once again back you up on Lenovo. You really can't go wrong with one of their higher end laptops.