Druid's Nature Bond and Paladin's Divine Bond -- Pages 15, 16, 20, & 21.
I've seen a bit of discussion on these that it is really nice to have a choice not to summon a mount or an animal companion. I agree. I just think that they should get both. Getting the divine weapon only 1 time a day is nice, but would it really be that game breaking if he got it along with his mount? I also really like the idea of the druid getting a domain. But why shouldn't/can't all druids get a domain whether or not they have an animal companion?
I really don't think that is too much compared to the changes to the fighter or barbarian classes.