I've always been in favor of different summons/planar bindings & allies, since those spells are very unexciting as default. I think people barely use the summoning spells at all due to the superiority of other spells of the same level. They don't last long, and die even quicker.
I really enjoy the scripting of all the summoning spells like they are on Daggerdale (2), where they were made more like the PnP version. So each summon was some random outer planar being, and could depend on alignment, for example: Celestial badger / fiendish badger. I remember at a certain summon level you could even call forth a Babilith. The planar binding spells were tougher to get the hang of, but were more powerful in spite of it. Like in PnP you'd have to break through the SR of the creature, and get a successful charisma check, and the further the creature was from your alignment the more difficult it was to bind. I remember if you were evil and failed to bind a good aligned outsider, he would turn hostile, and if you were good aligned and failed, he'd just be neutral and stand there uncontrolled.
