Equable

[PussyCat]

Equal and uniform; continuing the same at different times;
-- said of motion, and the like; uniform in surface; smooth; as, an
equable plain or globe.

[Rihanna]

Not easily disturbed or angered; calm and even-tempered.

[Hina Muqadas]

always being pleasant:

[Sonia]

(of a person) not easily disturbed or angered; calm and even-tempered.