Actual reality politics in this country aside (i.e "It's never going to happen"), the Parliamentary systems of Britain, Israel, Japan, Germany etc. where multiple political parties exist and can have an actual 'piece of the action' to the extent of sometimes getting to be in charge of a portion of the actual Governmental Administration or at least real input on some pending legislation or governmental policies is at least superficially attractive.  

The ability to hang up everything to get your own way by one or more minorities is both the strength and the weakness of those systems, however. 

 Just as the 2/3 Senate super-majority requirement for some things is for our system.