One big one I forgot, the great Vladimir who started the Bitcoin Forums, also runs with Vladimir's Bitcoin Information Security Consulting Service. I want to say there is a mining pool as well, but I am not sure if that is still up.
Another big one, the great Matthew N Write https://bitcointalksearch.org/user/matthew-n-wright-24749 of Bittalk.Tv http://BitTalk.TV , tune into it daily also runs with DialCoin https://dialcoin.com/, Bitcoins in 30 seconds, worldwide. I just wanted to give a quick shoutout to Matt for having two taglines that are not necessarily catchy, but way memorable, as I remembered both those lines right after thinking of the sites they are part of without having to look it up.
DialCoin is and features seal.
I know I did get into multiple things when I had the time, hard not to love and want to make better so many facets of Bitcoin, if I had more time I think I would double genjix' list lol