I don't use much pellet in my bunnies diet, but the few ones I've tried are mainly from Bunny Nature. They usually are very appreciated and I think the new formulas ("KaninchenTraum" which I guess in english is called "Rabbit Dream") are even better then the older ones ("Green Dream") because the first ingredient used to be alfa alfa , now it's meadow grass, including a lot of different plants. So basically now there's more fibre, and less calcium, I find it more adequate for adults. I've also tried the organic food "Bene Terra" (Oxbow) and I think it's really well formulated, but only one of my bunnies liked it.