Omea – one of the most fully featured RSS readers out there; can get a little slow as its database grows; free in its basic version, also has a commercial, advanced version with more features.
Mozilla Thunderbird – Mozilla’s e-mail and RSS reader, supports skins and add-ons.
Awasu – RSS reader with a customizable user interface, the ability to synchronize with other readers, bookmarking and annotation, and republishing of your feeds.
RSS Bandit – RSS reader that offers organization of your feeds through folders, as well as synchronization across several installations
GreatNews – integrates with Bloglines, and offers a very fast way to browse through your feeds.
IntraVNews – an RSS reader that integrates with Microsoft’s Outlook.
SharpReader – requires .NET framework, lets you organize feeds into folders, integrates with Feedster, can display new items via system tray popups
eCruiser – an RSS reader in Japanese
Juice – a pretty basic RSS reader
Opera – Opera web browser comes with a fully featured RSS reader
FeedDemon – Newsgator’s feed reader offering a high degree of customization, newspaper-style feed reading, synchronization with other Newsgator products, and feed search
Snarfer – a free RSS reader, with key features being river of news style view, embedded video display, synchronization with Bloglines, powerful search and filtering
Active RSS Reader - simple RSS reader with a very small hard disk and memory footprint
Feed Amasser – a very lightweight, freeware RSS reader
FeedExpress – a freeware, open source RSS reader; quite basic, but with some nice features, for example CSS customization
Anothr – RSS reader/bot for Skype/Gtalk/MSN
Crackfeed - a tiny systray based application that notifies you with RSS news as they come
HappyFish – RSS reader and podcast client, requires .NET 2.0
Attensa for Outlook – RSS reader that fully integrates with Outlook, support OPML import/export, scheduling, republishing, and advanced feed organization
Briz RSS Reader - a very simple RSS reader
Particls – desktop RSS notifier and ticker with lots of options, also has a Firefox plugin