I've been though a dozen of different lenses, zooms, primes, Ls, non-Ls and still consider this one to be the best IQ for the buck. Whenever I look through the pictures after the shootout and see something breathtaking - 9 out of 10 it was done with the 85mm f/1.8. If left with the choice of the only one lens - it will be the one.
I also own 85mm f/1.2L II which is a true masterpiece as well, but I can hardly find any difference above f/2 between them IQ wise, while autofocus is much faster on non-L. So to answer the popular question of 1.8 vs 1.2L - get both if you can afford 1.2L, get 1.8 otherwise.