In the chapter "Technique 20: Downloading from Newsgroups" Woody states...
"I, Personally, use Giganews. It's fast. They claim 99%+ completion. Binaries stick around for 90 days or more."
(Obviously this was written before Giganews' last retention upgrades to 100 and then to 120 days.)
The chapter is one of the most comprehensive "how to" instructions on Usenet we've ever read, and is an excellent read for anyone looking to learn how to use Usenet (especially good for first time users!).
If you're running on Vista, purchase a copy of "Windows Vista Timesaving Techniques For Dummies" and check out the mention of Giganews on page 216.