Residential real estate is a tale of two markets - luxury and everything else.

According to Christie's International Real Estate: "The world's top cities experienced an explosion in luxury home sales during 2013, fueled by pent-up demand, increasing consumer confidence and robust stock market returns. In 2014 however, prime property sales in these markets settled into a stable growth pattern that seems relatively tepid".

Based on sales prices, average cost per square foot and number of sales, the luxury real estate arm of Christie's - the fine art auction house - listed the world's top 10 luxury real estate markets in its recent "Luxury Defined" 2015 report.

No 10 Toronto, Canada

Mean Girls' mansion can now be bought at $12 million in Toronto, Canada. [Photo / IC]