Good Online RSS Readers?

Lately I've been trying out new RSS readers in the hopes of finding a better way to (a) manage the blogs I read regularly; and (b) discover interesting news items from blogs I don't read.

My criteria for the perfect RSS reader are that it:

• Not be tied to a single computer (i.e., it must be or sync with an online service)
  
• Have functions that help me organize the material I'm reading (e.g., tagging)
• Rank posts by potential interest to me
• Mark posts that I want to check up on
  
• Suggest items in feeds I haven't subscribed to
  
• Enable me to (relatively securely) read password-protected feeds.
  

I've tried Bloglines, NewsAlloy, Rojo, and Google Reader.  My takes on the services:

Bloglines:  I was using this for a while, but was never satisfied with it.  There's no tagging; feeds are arranged in folders.  This doesn't work for me because there is overlap; I read a lot of sites about feminism in fandom, and they deserve both tags rather than having to choose whether they're feminist blogs that focus on fandom or fandom blogs with a feminist focus.  There's also no ranking or discovery of posts, or viewing of password-protected feeds.  I can mark posts with the clip function, but it's unweildy.  There is a mobile version available.  Bloglines can sync with Greatnews, but I've never gotten around to trying that.

NewsAlloy:  There doesn't seem to be any way to tag feeds, only posts; I have to use "channels," which appear to be folders by another name.  In addition, it's hard to call up your own tags, because the default (which I can't seem to change) .  There's also no way to change the name of the feed, and the name is short.  Discovery of posts from feeds you're not subscribed to seems to be nonexistent - you can "rate" posts, but can't see the highest rated posts.  On the bright side, there seems to be an option to check password-protected feeds and a mobile version, you can subscribe to searches as feeds (Bloglines does this too), and you can save posts in an archive folder.  NewsAlloy also has some performance issues.

Rojo:  the tagging function is nice, as is the discovery of posts.  If NewsAlloy is the Outlook Express of online RSS readers, Rojo is del.icio.us.  Like del.icio.us, the posts that become popular tend to be those that appeal to a certain type of computer geek (and not necessarily to me).  Rojo was the best at finding new posts in feeds I didn't subscribe to, but has no way of checking password-protected feeds.  There does not seem to be a mobile version of Rojo, nor does there appear to be any way of keeping track of posts I like.

Google Reader:  Google Reader does tagging and saving extremely well.  If I tag a feed "technology," all posts in the feed will default to having that tag.  If I want to mark a post for later, I click on a star and I'm done.  There's no social side, however, so discovering new feeds/posts is difficult.  There's a search function, but it puts feeds and posts together and doesn't seem to adjust for recency.  The interface is a bit clunky in places (it's notorious for not having a "mark all read" function).  There's a mobile version, but it seems to be optimized for cellphones rather than PDAs.

I'm not sure what I'll wind up sticking with.  NewsAlloy has a lot of promise, but it's too buggy right now to use on a regular basis.  Rojo is neat for finding new items, but wasn't so great for reading news.  Google Reader is the most usable at this point, but is the worst for finding new content.

Those of you who read a lot of blogs on multiple computers, how do you do it?  Are there any other RSS readers I'm missing out on?  Any tricks for the readers here that would address these issues?