I can't compete with you professional travellers for longest flights, with all my trips being currently under 7000 miles.
Must get out more when conditions allow:

6896 miles, Buenos Aires EZE - London LGW, British Airways B747-400
6565 miles, London LHR - Kuala Lumpur (old), Malaysia Airlines B747-400
5974 miles, London LHR - Tokyo NRT, Virgin Atlantic A340-300
5863 miles, London LHR - Sao Paulo GRU, TAM B777-300ER
5829 miles, Sao Paulo GRU - Paris CDG, Air France A330-200
5806 miles, LAX - Frankfurt, Lufthansa B747-800
5805 miles, Tokyo NRT - Amsterdam, KLM B777-200
5709 miles, Bangkok (old) - Amsterdam, China Airlines MD-11

KT