You must get the Japanese KI-43, tier 2. That will not take long time.
Its just so much fun to drive. Gives you a good idea about the japanese as well.
Overall, I say Brits as others, atleast for the lower tiers.
The US also have great dog fighters. The Corsairs later for example, and earlier then that also. For Mid tier planes, US have better planes then the brits. Corsairs, the Cobras.
Russians have generally great planes, not always the best but in some tiers they are.
Lagg 35 is by far the best tier 3 plane in the game.
LA-5 is by far the best tier 11 plane in the game.
The Mig-15 Jet tier 20, is in another dimension compared to other countries Jets.
So all in all, low tier, mid tier and top tier, Russians have the best planes.
They also have the absolute best bombers in the YER line.
Still, you will have time to play them both. Taking countries up to level 5-6-7 goes pretty fast and the cost of airplanes is not that much.
Mix it around.
Get a Lagg 35 russian at tier 3. Get a japanese KI-43 at tier 2.
Get the US tier 1
Try out Brit Beufighters and Spitfires.
And for level 0. If you want to practice and be a little on top: Russians Reserve planes is far better then any other countries. They turn alot faster.
Its the only reserve plane that can take on tier 4-5 planes and get away with it.
In Arcade the German BF109 F4 does not fly as it should and can turn fight pretty well, otherwise Germans are BnZ fighters. They take altitude, dive in, fires and take altitude again, rince and repeat.
Pure dog fighters and great planes at low tier, Brits, japanese or US.
Dont miss out on the low tier Beufighters. Both the tier 5 and 6 are extremly good.
Low tier fights is among the most fun anyway. Tier 0-3 is a blast.