From Wikipedia

Terminal 3 - Bangkok-Suvarnabhumi, Barcelona, Gibraltar, Helsinki, Lisbon, Madrid, Singapore, Sydney, Vienna.

Terminal 5 - Aberdeen, Abu Dhabi, Abuja, Accra, Algiers, Amsterdam, Athens, Atlanta, Bahrain, Baltimore, Bangalore, Basel/Mulhouse, Beijing-Capital, Berlin-Tegel, Boston, Brussels, Bucharest-Otopeni, Budapest, Buenos Aires-Ezeiza, Cairo, Calgary, Cape Town, Chennai, Chicago-O'Hare, Copenhagen, Dallas/Fort Worth, Dar es Salaam, Delhi, Denver, Doha, Dubai, Düsseldorf, Edinburgh, Entebbe, Frankfurt, Geneva, Glasgow-International, Gothenburg-Landvetter, Grand Cayman, Hamburg, Helsinki, Hong Kong, Houston-Intercontinental, Hyderabad, Istanbul-Atatürk, Jeddah, Johannesburg, Kiev-Boryspil, Kuwait, Lagos, Larnaca, Las Vegas, Los Angeles, Luanda, Lusaka, Luxembourg, Lyon, Manchester, Mauritius [ends 31 October], Mexico City, Miami, Milan-Linate, Milan-Malpensa, Montréal-Trudeau, Moscow-Domodedovo, Mumbai, Munich, Muscat, Nairobi, Nassau, New York-JFK, Newark, Newcastle upon Tyne, Nice, Oslo-Gardermoen, Paris-Charles de Gaulle, Paris-Orly, Philadelphia, Phoenix, Pisa, Prague, Providenciales, Rio de Janeiro-Galeão, Riyadh, Rome-Fiumicino, St Petersburg, San Diego, San Francisco, São Paulo-Guarulhos, Seattle/Tacoma, Shanghai-Pudong, Sofia, Stockholm-Arlanda, Stuttgart, Tel Aviv, Tokyo-Haneda, Tokyo-Narita, Toronto-Pearson, Toulouse, Tripoli [resumes 25 March], Vancouver, Venice, Warsaw, Washington-Dulles, Zürich