Halp!

I'm a little torn with what to do, so I'm coming to the AP knowledge base for some more opinions.

Back story:
Went to a friends 30th on the weekend, said I'd take my camera and walk around and get some photos. I knew the lighting would be low, so I took my flash and the 50mm f/1.8, I have a 40D.

Needless to say, I was annoyed most of the night, 50mm on a crop sensor is a pain. I had my ISO cranked as well, and I have to say that the noise from the 40D isn't fantastic in the higher ISO's....

Which leads me here:
Sell the 50mm, and get myself a prime at the sub 35mm mark
Perhaps get something along the lines of the 16-35?

Open to more suggestions, I don't think it's time to sell the 40D and go full frame, not yet.