If you haven't used a rangefinder before, be aware the "style" of shooting is quite different than with an SLR. Some folks don't make the switch easily.
That said, there is obviously a wide range of options. Among the models currently being produced, I'd suggest looking at the Bessa-R models that use Leica-M mount lenses. The Voigtlander lenses, while not as fast as the equivalent Leica models, are quite good, and far more affordable.