The 50mm is nice by all reviews. You got the better of the common options (others start f/1.8, as does mine). The Tamron has a number of good reviews online. I would say the 135mm prime is not too great. It's covered inside the range of the zoom, and for being a prime lens is somewhat slow (I've seen a number of 135mm primes at f/2.8 in my online readings).
I would, however, suggest something in the 28mm-35mm range as well. I was very hindered by indoors shots with my 50mm for many years when I started out. It was just too close to frame anything other than closeups. The wide lets you stand closer and frame what you like much better.
EDIT: Whoops, I see you have the SSC 50mm. Definitely a keeper, from what I've read!