Imagine that all those saved mailing list posts, downloaded articles, and feed subscriptions were printed on paper.
How big a stack would you have?
Don't make your computer the digital version of one of those crazy people's houses where you have to scoot around between teetering piles of mouldering news.
Be realistic about the amount of time you spend "keeping up with sites". Pick a reasonable number based on your available time and how much of it you want to spend online. Visit the others when they come to mind.
I am a big web geek. I know many many other web geeks. I know many wonderful sites. I have chosen not to use a feed reader to keep track because I have pared myself down to a handful of sites I look at every day. I like to see them in context, with the style the authors chose. Somehow it makes me hear their voices more.
Deciding not to chase around trying to keep up with everyone else's every posting or 50 hot sites was the right choice for me. My work overloads me enough; I don't need an impossible-to-keep-up with to-do list at home.
Find your balance and let go of the rest.