The original saddles that came with the Giants were a low spec. gel saddle and we replaced these with a Serfas RX model.
These worked fairly well, however we have found that gel saddles loose their effectiveness after a while, are sweaty and you still end up with a 'numus bumus' after a while!
In an attempt to find 'Saddle Nirvana' we have now moved to trying the Brooks leather saddles. We both started with the B67, my wife has found hers to be quite comfortable from the start and has continued to use it.
As far as I was concerned I couldn't quite get on with my B67 it didn't suit my behind and my less upright riding position. I found that it was too short for me and I have since changed it to the Champion Flyer which it is longer in the body and slightly narrower. It also has a slightly thicker and harder leather and has taken slightly longer to break in than the B67, however it is now much more comfortable.