the best question is what are you going to shoot, zooms are very helpfull in tight spaces and for digitals, primes have better quality but you have to move phisicaly.
I bought the 85 1.8 and I love it although I mostly use the 50mm 1.4 because of the multiplying factor in my rebel.
I got this gig on covering a small beauty show and both the 85 and the 50 shined, the light was enough for me not to use any flash and at F4 the images where very sharp (although you need to be carefull with depth of field)