Got to be for me a couple of WW2 icons to go with the brilliant new tools from the same era that have been released recently:-
A 1/72 B29 Superfortress, how good would this look on the shelf with the same scale B17 from last year, with a C47 Skytrain in the middle................ &
A 1/48 Mitsubishi Zero, which would make a fantastic "Dogfight Doubles" partner for either of the two American reecent releases,the P51 Mustang or P40 Warhawk.................
Or one from cold war era:- (which has been mentioned by other posters)
A 1/72 Blackburn Buccaneer, would make a great pairing as an Ark Royal display with the superb RN Phantom Airfix gave us recently.