I was told by a top bowyer that limb performance is a factor of design/glass, and within certain parameters the wood makes little difference.
That being said, it's pretty much a given that some of the toughest & most durable limb woods include stuff such as bamboo, hickory, locust.
Hard to beat yew or nicely figured elm for looks.
I personally like the looks of walnut limbs.
My next bow (on order and should be done sometime this Summer) is going to be made of a very fancy piece bocote (the bowyer and I selected the particular piece of wood from his stash) with bamboo fades and bocote veneers...