I used NNW and Gruml, but for the past 6 or 8 weeks I've just been using the Reader web app. I don't know what prompted the switch, but it's been easy and I don't miss having a native app at all.
Gruml is a GReader desktop app for Mac OS X. It works pretty much like Google Reader except that it is your desktop app. It remains in-sync with GReader all the time i.e. any changes done in Reader or Gruml is reflected in other in real time. It also allows you to tag, share and post your feeds.