Airplanes on Static Display at at the Soviet Aviation Museum (Aviâcijas muzejs)
If you're a fan of Tom Clancy novels or the Cold War in general, then this little known museum located to the right of the airport terminal is a must see when in Riga. Walk among Soviet helicopters and planes of varying age and size and if you're lucky maybe the owner of the museum will even fire up one of the engines if he has the fuel. Sorry, the aircraft are currently only for viewing, not for flying. Definitely call ahead before going. If it's closed, you can still take a peek at it over the wall.
And from www.rigathisweek.lv:
One of the richest collections in Eastern Europe, the museum has war, passenger, sports and training planes and helicopters. You can see almost all the models of the famous Soviet MIGs, among them the world's fastest war plane MIG25.
Also some ground level shots at www.travel-images.com and also at www.airliners.net.