Slang for cool.
And I would love to see the P-38K, and the P-51H (yeah, yeah, I know).
P-38K saw no combat. Sorry.
He-111 would be nice. However, I feel that some of the current planes in the set need to be updated. Yaks, Tempest, P-40s, A6Ms, B-26, Ju88, FM2, F4F, and C.202/205 just to name a few.