Haha, this is really kicking off now! Anyways, from most fav to least fav: 

Shaman (For obvious reasons, like a ghost-pet teaching spider powers!)

Avatar (I can make this work, perhaps with a living pet as the medium for some ancient spider-associated hero.) 

Warden (Would be awesome if my PC could still have the ghost pet and a specialization that so heavily involves acting like a spider.)