Sigma 30mm 1.4
canon 50mm 1.4
Canon 85mm 1.8
Indoor, low light, portrait stuff only.
I'd probably look to get them all eventually, but the first one will be an instant buy along with my 7D/15-85IS bundle, the other two will probably be at least 6 months down the line.
I know there is no 'best' answer, but I'd like your opinons, and perhaps some example shots. I have a slight concern whether the 30mm 1.4 distorts faces at all? I had an 85 1.8 for a while and found it long but manageable indoors.