I use Google Reader. It's a pretty handy way to navigate the internet (though does white-wash all the websites you read), and it's nice to keep a track of Tumblrs. However, I've recently removed a whole bunch, as they offer me nothing. Perhaps even less than nothing.
Tumblr touts itself as 'the easiest way to blog', which it indeed is. The ease of this, as deemed by most users, seems to be appropriating images and quotes from other Tumblrs. Who get them from elsewhere. It leads to a whole culture that is very disingenuous, especially when the source isn't even stated.
Of course, there are Tumblrs that I enjoy, the authors of which provide a lot of original, worthwhile content. See at: Timmy, and Lucy.
Are there any Tumblrs that you would recommend reading?