85 1.8, 100L, and 85L, I've used all three, though I don't own any. Three fantastic lenses if put in the right hands and the right budget. The 85 1.8 is the best bang for your buck, that's for sure at 359$ right now at B&H. But some people have more bucks than others and that's where the 85L steps in. This monster is an absolute beast, but you gotta know how to handle it. I like to call it a "speciality" lens. If you're getting this lens, it's to shoot it wide open, and that takes a lot of skill. The DoF is so thin that some focussing techniques don't work, such as focus and recompose. By pointing your lens up and down, the subject is already out of focus. And as for the 100 range, I never used the f2.0, but the L is a katana, sharp like no other lens. Shot flowers with it for a project and the results are astonishing. But as I always say, sharpness is overrated, but that's just me. Although for portraits, I find 100mm kinda weird to work with. Again, getting personal here.
Best way to find out is to rent the lenses or get them for a short while to play with them, as I did. I had to choose between the 85 1.8, the Sigma 85 1.4, the Samyang 85 1.4 manual focus, and the Zeiss 85 1.4. Tried them all, and decided to save up for the Zeiss.
Oh and screw the IS version. It's gonna cost 800$-1000$ and it's gonna come in yeah 2547. You want something, get it. Oftentimes, the said "replacements" are way off what we predict. I got a 24-105mm a bit before the new 24-70 f4 IS was announced, and I couldn't be happier.