I don't know if any particular lenses are better than others for sky imaging. As a generalisation, same factors as with telescopes apply. The bigger the aperture (lower f number) the more light you can get, helping to keep exposure times down. A suitable prime lens will allow you to get lower f values, but of course they're fixed focal length. You can also consider a zoom, but if you do be aware that many can suffer from "zoom creep" when angled away from horizontal.
_________________Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.