The Watchtower Observer was what I "grew up" on - long gone. You can see what it looked like here:
http://constitution-first.org/Concordat.htm
Then there was CARM which is still on the go but focussed on Evangelical/JW debate:
http://www.carm.org/religious-movements/jehovahs-witnesses
Watchtower Information Service more recently was excellent.
Beyond Jehovah's Witnesses was another excellent site precisely because it was so mild and definitely not apostate-in-your-face style.
But among those still running I would highly recommend Spotlight Ministries run by Vince who helped persuade me the Witnesses are wrong even if he did not succeed in convincing me Christians are right: