For an adult rabbit, make sure the pellets are made from Timothy hay, no alfalfa. Look for high fiber and LOW protein in a pellet. Protein should not be over 14%. Fiber should be at the very least 18%, more is better. And, of course, no junk in it, ie, dried carrots, sunflower seeds, etc. Just pellets. All of the American brands stated above are good ones (sorry, I don't know about European brands). If you need to get a bag at a pet store, Petco sells Zupreem's "Nature's Promise". My buns hated Oxbow, but love Zupreem and it's fiber content is excellent while its protein is acceptable. Stay away from KayTee if you can. I've never seen a pellet of theirs that wasn't junk.