Frequent readers have seen me pushing SauceReader as my RSS newsreader of choice for a while. I use it everyday, at home and at work – it's that solid. That being said, it is a memory hog and there isn't a way to synchronize my feeds between home & work. So…I've been testing out some of the more popular online newsreaders. The conclusion: I'm in love with NewsGator.
NewsGator's free Online Edition is awesome. It's got an outstanding, clean interface and does exactly what you want it to do absolutely free. It offers folders for organizing feeds, the ability to import & export feeds as OPML, syncs up with paid versions of NewsGator (Outlook, Mobile, POP, etc), and accepts any feed type. NewsGator Online even lets you publish a blogroll (as a partial or complete list of feeds) and offers a "clipping" service, similar to del.icio.us. (More info)
For a pretty complete, online, free newsreader – it's pretty dang hard to beat NewsGator. I'm making the switch permanently.
Update: Here's some NewsGator Tools to help out your online experience:
Firefox 'Right Click to Add Feed' for NewsGator Online
Internet Explorer 'Right Click to Add Feed' for NewsGator Online