We had a referendom on proportional representation and it was rightly rejected.
Proportional representation has caused a lot of problems in Italy.
My prefered electoral system is that of Australia: optional preferential voting for local representation in the lower house and STV (Single Transferable Vote) for State representation in the senate. It tends to produce a reasonably stable government based on a quasi 2 party system (Labour on the left and a stable coalition on the right). The Senate on the other hand tends to be more proportional with smaller parties achieving the required quota and often holding a very influential "balance of power".