Creating a stable, two-party only system à l'Américaine in any parliamentary democracy would be quite difficult. There are two things that make the US system operate as it does:
1) With a limit of 435 representatives, each Congressman now representes a district with an average population of over 750 000. That exceeds by a factor of three the average size of a Lower House district in Japan and more than 7x that average population of a riding in Canada, a UK constituency, or a French circonscription. The smaller size of Canadian and European electoral districts is more conducive (IMHO) to third parties gaining footholds, even in FTTP systems, than mega US style districts.
2) The two party system is maintained through the party-primary system. While a couple of states have open primaries (LA and CA at least), most states maintain a party-primary system which, combined with partisan decennial reapportionment, creates a situation where the vast majority of the districts are decided by the results of the "dominant" party's primary.
Actually, I should probably include partisan control of reapportionment as a third point. Look at a state like Ohio. Even though it has voted for Obama the past two elections and only gave Bush narrow margins of victory in his two elections, the current apportionment was designed to create a 12-4 Republican majority in its Congressional delegation by the Republican controlled state legislature.
So in other words, be happy Canada or any other enlightened country doesn't suffer from this stiffling, jury-rigged system we call American governance!