Without some more specific parameters for what your needs and wants are, I suspect we'll keep going until nearly every extant rangefinder has been mentioned.
That said, here are my comments.
I've used and sold a number of Canonets over the last 30 years. I've not seen or heard of a dog (or a mediocre lens) among them from friends or customers, as long as they are decently cared for. The 40mm f:1.7 I have now rivals the Summicron 50 and 40's that I've used for over two decades for contrast and resolution, especially at mid apertures. So I can't see it as performing poorly relative to other good glass from Yashica, Konica, Olympus, or others. I'd check those bad samples for poor service, fungus, etc. The QL film loading system on the Canons is very nice. I miss that in SLRs after trading my FTb's.
I'm with rbarker in recommending the current and recently discontinued offerings from Cosina Voigtlander, the Bessa R, L, T, R2, R2A, and R3A. There's a lot of good information on them at cameraquest.com, so read that carefully and see if any strike your fancy and fit your working style. Their lenses are very fine performers, especially at their prices.
I also like the Agfa Isolette and Record III that I have. Smaller and lighter than an SLR, and fit in a large pocket when folded, plus the larger negative is a big positive. I use them with a Gossen Digiflash meter that's small, fast, and accurate.
Lee