Tangible God
Lets all love Lain
Sadly Tiberius, they are. They're responsible for Tatooine being a desert world.
But in relation to this thread's topic, I'd say the Empire at it's zenith could take on everybody.
Tens of thousands of Star Destroyers, The Executor, The Death Star, and the countless numbers of lesser craft the Empire used to control the ENTIRE galaxy. They would need billions if not trillions of stormtroopers (who were brainwashed recruits, not clones) to maintain their "rule through fear of force" doctrine. With men like Palpatine, Vader, Thrawn, even Pelleaon, and Tarkin controlling their vast fleets and armies, they'd be invincible one on one.
The Empire was stated to cause the single largest military buildup the known recorded galaxy has ever seen. That includes Revan's Sith, the Rakata, Separatists, Old Republic, Clone Army, all of 'em.
The Yuuzhan Vong feared to take on the Empire, that says alot about their chances. They were no fools, militarily, they wouldn't risk annihalating their whole civilization out of pride. So they waited till the Empire declined and the New Republic was war-torn.
The Death Star, by visual comparison, appears to be larger than the Star Forge, and it seems the Star Forge didn't even have a shield, where as the DS2 had one. One shot from the Death Star, that would take like 20 seconds to fire, would totally destroy the Star Forge, despite it's abilities.
The Empire would chew up any fleet who took it on.