This is a question faced by many couples who want to reside in the United States. All these visas are spousal visas, however, only spouses of US citizens may be given K3 visas.
These visas authorize entry to the US but unlike the other two, the K3 Visa is essentially a nonimmigrant visa. The K3 holder will have to adjust his or her status within the prescribed period or else he or she will face removal or deportation. With regard to the IR-1 and CR-1 visa, these are already immigrant visas granting the holder legal permanent residence.
After taking note of the limitations of K3 visa, one may think that IR-1 or CR-1 visas are better alternatives. Nonetheless, the mode of visa processing might change his or her mind.