MMP is the most proportional, also the one most likely to run into constitutional challenges, and the one most likely to fail in a referendum due simply to how difficult it is to explain to people not interested in electoral reform, ie, almost everyone.
If the NDP had agreed to go to ranked ballot or single transferable vote as at least an interim measure, something could have happened. NDP went for broke and rolled snake eyes.
Electoral reform is dead for at least the next 10-20 years. The Liberals are feeling burnt for trying. The NDP are as far from power as ever. The CPC just won't. And the Bloc will remain spoilers.