No specific app recommendations from me, however, I personally prefer to browse around for apps on http://androlib.com from my PC, where you can see all the info, reviews, screen shots etc on a nice single screen...  If you install one of the "Barcode Scanners" that support "QR Codes"  (I like the one from the ZXing Team) you can use it to "take a picture" of the QR Code on the page of an app you like, and it will take you right to Google Market on your phone to install the app.