Don't overrule a mixed breed immediately. When it comes to having a pet, mixed breeds will make just a good of pet as a purebred, as long as it was handled properly as a baby and treated well. Mixed breeds are generally unique, varying from one litter to the next. They are also much cheaper then their purebred cousins. Really, the only downsize to getting a mix is that you won't have a very accurate guideline as to what the rabbit's temperament will be like when it's older, how big it will get, or what it will even look like.
Some of the most popular pet rabbit breeds are smaller, and easy for children to handle. Remember that rabbits are fragile, and not the best pets for young or rowdy children. The bigger the rabbit, the better it will be with kids. Large breeds are very docile, relaxed, and can usually take a lot more then a tiny, bouncing, finicky Netherland Dwarf.
MINI REX - The Mini Rex is known for its soft, thick, velvety fur. They get to be about 5 pounds at maturity.
HOLLAND LOP - I can go off about this breed. My personal favorite! Known for its lopped ears, muscular appearance and adorable big head, this breed maxes out at 4 1/2 pounds (usually 4 tops).
DUTCH - My next favorite. If I could choose another breed, I think this one would be it. Dutch rabbits stay 6 pounds or under. They are known for their distinguishable, beautiful pattern.
NETHERLAND DWARF - This breed stays near 2 pounds. They are very small but very fragile. Netherlands have been known to be nippy and bite when agitated. They are very bouncy and energetic, but also temperamental. Netherland Dwarfs have tiny ears and small, round bodies.
MINI LOP - Even though it's considered a "Mini", this lop gets to be about 6 pounds at maturity. They are sweet, gentle, and good with kids. They have longer lopped ears then the Holland, and they are much bigger.
HIMALAYAN - The Himalayan is one of the oldest rabbit breeds. They are a medium sized breed, getting to be about 6 pounds at maturity. They have a long, "snaky" build (called "cylindrical" type, similar to a cat), and look very unique. They always have red eyes and a white body and colored ears, nose, feet and tail. They are very docile and easy for even children to handle.
POLISH - The Polish is one of the smallest rabbit breeds. They get about 3 1/2 pounds at maturity. They are like Netherland Dwarfs in the fact that they are somewhat jumpy. They have very fine bone and are very fragile.
There are many, many other rabbit breeds, and all can make wonderful pets. Remember: If you are prompted to get a rabbit as a small child's pet (given that you, the adult, still takes full responsibility for the rabbit and takes care of it), a bigger rabbit is better. Smaller breeds are generally more jumpy, but more fun, then the lazier, more laid back, larger breeds.
Of course, it all depends on the rabbit. My bunny Cinnamon is very laid-back and great with children. I expect her future babies to be the same way. Then there will be occasional large breeds (like a Flemish Giant, the biggest rabbit breed there is), that'll be jumpy and nippy.