The fee page of 21.co is especially well made. It would be great to have such a graphical overview implemented into Bitcoin Core directly. The fee selection bar isn't quite as informative.
If you enjoy good old school graphic charts I can only recommend:
http://bitcoin.sipa.be/Site shows hash rate and block version (including adoption of BIP's).
What are your favorite sites for hash rate distribution (anything other than blockchain.info, static graphics preferred)?
Is it possible to easily source the information mentioned in this thread from Bitcoin Core?
ya.ya.yo!