For the given compounds:
(1)
; L.P. on Nitrogen is delocalised.
(2)
; L.P. on Nitrogen is localised.
(3)
;
L.P. on Nitrogen is delocalised due to conjugation with both 
(Hence least basic)
(4) CH3−CH2−N¨H−CH2−CH3; L.P. on Nitrogen is localised.