For me, the most exciting difference is Pathfinder's Combat Maneuver Bonus and Combat Maneuver Defence.
All the things you might want to do in combat besides hitting someone - tripping, disarming, grappling, throwing sand in their face, are covered by a convenient subsystem. Grappling is still a bit of a headache, but on the whole it's much more streamlined than 3.x
Also in 3.x, with your racial ability score modifiers, most core races net a +0 (+2 to one, -2 to another), while in Pathfinder they net a +2 (+2 to to two, -2 to another). Elves are more intelligent, dwarves are more wise. It's a minor difference, but it caught my eye.