Not only for the concept, but for gaming purposes, Rogue/Ranger is by far the coolest. Two-weapon fighting with massive sneak damage... rox the most.
Also, a combo tip: there's a sword called Rogue Blade, I believe it's in Savage Species, which is really powerful for rogues, because it makes you permanently under the effect of blink (like the spell), and when you're blinking, you attack like an invisible creature, which means all your attacks are sneak attacks.
Cool, huh? eek