Personaly i like some Rhyme Asylum when it comes to rap And have never found any others who could compare to them.
and when it Comes to Ambient /electronic I like some Boards of Canada, Aphex Twin, Osiris 1, Exists Strategy, Amon Tobin.
But i am open to any suggestions so feel free - here's ome of mine.
AMBIENT/ELECTRONIC
Boards of Canada - Dayvan Cowboy (amazing video and song - Chill out almost)
Boards of Canada - Peacock Tail (very chill)
Amon Tobin - Easy Muffin (chill)
RAP/HIP HOP
Rhyme Asylum - playlist because i cant pick out a couple of there songs there all so good.
Strongly recommend that if you like anything close to any of these generas then you give them a listen.
And if you like don't hesitate to ask for other suggestions