In my opinion very interesting german aircrafts to make are:
Blohm und Voss BV-138 (flying boat) maritime reconnaissance aircraft
Blohm und Voss BV_222 (flying boat) maritime reconnaissance aircraft (I know that IAF.116~Jagr made something but the project is probably dead)
Dornier Do-18 (flying boat) maritime reconnaissance aircraft
Dornier Do-24 (flying boat) maritime reconnaissance aircraft
Dornier Do-17 bomber
Dornier Do-217 bomber
Focke-Wulf Ta-154 night fighter
Heinkel He-100D fighter - very good and interesting construction, not used by the Luftwaffe (maybe good
)
Heinkel He-112 export fighter (Spain, Hungary and Romania used them)
Heinkel He-115 seaplane torpedo bomber
Heinkel He-116B long-range reconnaissance aircraft (the Luftwaffe used six planes) - very beautiful aircraft I think
Heinkel He-117A heavy bomber (I know that flying_fat made something but the project is probably dead)
Heinkel He-219 night fighter (I know that frankenplane exist, but I hope that the He-219 will be a new slot plane)
enschel Hs-123 dive bomber and close support aircraft (like above)
Henschel Hs-126 reconnaissance aircraft
Junkers Ju-88 late version like the Ju-88S bomber and the Ju-88G night fighter
Junkers Ju-188 bomber and reconnaissance aircraft
Junkers Ju-388 bomber and reconnaissance aircraft - very beautiful aircraft I think
Junkers Ju-290 long-range maritime reconnaissance aircraft
Messerschmitt Bf109 early versions like the Bf-109C and D fighter
Messerschmitt P.1101 jet fighter - very interesting construction