Actually, it's still Green Goblin. Hobgoblin's a completely different person who just used more primitive versions of the Green's equipment (well, at the start)

Venom is Eddie Brock. The alien went from Parker to Brock since Parker rejected it and forced it to seperate from him. In the comics, Venom is actually on someone else now.

Villains we haven't covered:
Kingpin
Scorpion
The Lizard
Mysterio (could be done really well)
The Vulture
Carnage
Kraven the Hunter

And there are several Spider-girls, but the most common one is Peter and Mary Jane's daughter in one of the alternate future timelines. She's actually pretty kickass for a kid, being infected with the Venom symbiote but being able to control it.