Alternative printer cartridges for Deskjet

I own a Deskjet printer and due to more frequent printing I am going through ink quite frequently. I see that there are other types of ink available but in general, is the quality good and are they reliable? I hate to spend the money for the HP ink constantly but I will if it is the only type of reliable ink I can buy. Is there any type of ink that is preferred over another? I am going through about 3 ink cartridges a month.
