Rentals.com - Where Renters and Landlords Click - http://www.rentals.com - ( more details )
Most comprehensive rental / apartment listing database in the world includes single family homes and houses for rent, apartments, condos, townhomes, vacation rentals, and a variety of other rentals

RentSeeker - http://www.rentseeker.ca/ - ( more details )
Listings are available for all major and many smaller cities in Canada, including Toronto, Montreal, Calgary, Vancouver, London, Quebec City, Ottawa, Mississauga, and many more.

Apartments Booking - http://www.dobovo.com - ( more details )
Apartments booking in Kiev, Odessa, Lviv, Poltava, Vinnitsa, Nikolaev, Yalta, Kharkov and other cities of Ukraine. Online instant availability confirmation for your dates. Discounts. Free internet. City center.