I prefer #40
I like having the variety of a lot of late war aircraft, some we don't usually get to fly in scenarios, to choose from, i.e. TA-152, FW-190D-9, Spit XVI, Spit VIII, Typhie, Tempest.
My reasons why I don't prefer these -
#1 is better for the next 12-hour scenario, as mentioned by Brooke and others.
#17 is the same old early war British Spits I/V against the early German bf-109E/F. Want more mix than that. Also no buffs involved. Not sure how a pure fighter engagement will work out. What's the incentive.
#5 would be OK as there are some late war choices, just not as many, nor as out of the norm as in option#40..