@robmandu, you can use google gears to download all unread items for offline access, and then when you are connected, you can turn off gears, and it syncs what you’ve read with the server.
I have tried RSSOwl, Vienna, NewsNetWire, Sage, and Thunderbird, and I find Google Reader to be the best of the lot, by far. Syncing no matter where you are precludes anything from being duplicated in your list.
My favorite features are sharing articles, hotkeys, Suggested Feeds, “Google Recommended for You” articles, and feed discovery. There’s no limit to how many articles you can ‘share’ or star (bookmark), and you can search through the history of all of your subscriptions, just like in GMail. Also, there’s some hot Greasemonkey scripts for it. If you’re running Firefox, check out Lifehacker’s Better gReader.
I’m a reader devotee, and I don’t care who knows it. ;)
Extra hot tip: access reader through https: https://www.google.com/reader/