Both the Canon 85mm and 100mm lenses can be great portraiture lenses and are excellent telephoto lenses. I think the 100mm macro lens is slightly sharper than the 85mm lens. However, the 100mm macro lens is longer, heavier, and about $200 more expensive than the 85mm. I would say that the 85mm gives you more bang for the buck than the 100mm macro--it is more like a sleeper hit lens that Canon makes.
I have both lenses, and I love them both for different reasons. The 100mm macro is great for when I want to take a prime lens out for flower shooting. The 85mm lens is great as a compact, photojournalism-style prime lens for shooting. You can't go wrong with either lens.
I have not tried playing with the 135L lens. I've heard that is the best portraiture lens out there.