Right now everyone can get up to +6 initiative by feat and trat (Druid can get up to +8, with an extra feat).Nitpick: Rangers can go much higher. Favored Terrain adds to Initiative, and unlike Favored Enemy, it's very easy for a Ranger to pick the "right" Favored Terrain so that it will be in use the majority of the time.
Oh forgot about ranger favorite terrain. Nice.