Rabbits live in big groups in the wild and your domestic rabbit will also enjoy the company of other rabbits. In fact a single rabbit will get lonely unless you are prepared to spend a lot of time with it. So a pair of rabbits is a good plan as they can keep each other company.
The next question is boys or girls? Well, one of each will generally make the best long term companions. BUT! Unless you want to breed from them, you must have them both neutered - an operation that your vet can do. Two girls can be very competitive, however they do have the advantage that they won\'t be able to breed. The same is true for two males who will often live happily together, especially two brothers who have been reared together. If they do become aggressive towards one another after puberty (at about 3 months old) it may be necessary to have them castrated.
Remember - if you keep males and females together without having them neutered you must be prepared for a sudden increase in the number of rabbits you've got! Breeding is not an area that should be entered into lightly.