Google Reader is going away on Monday. ReplaceReader.com lists many alternatives, sorted by popularity.
Another RSS reader I didn’t see on their list that looks promising is Yoleo.
Also, Digg Reader is supposed to be released soon.
Update: Digg Reader is out. You can read more on their blog. I’ve only used it for a few minutes, but I think it may be my favorite RSS reader.
Update (2019-08-01): Looks like ReplaceReader.com is dead. I’m currently using Inoreader.