Where to stay and dive at Koh Tao?

Koh Tao was such a great experience back in the summer 2005 – so nice, so beautiful, so relaxed, great water and I loved the diving there. For my next trip to Thailand in August I’m still not sure if its going to be Koh Tao, but chances are pretty big – Benjamin has never seen it and I loved it, but this time I might go by plane to Koh Samui and with boat from there..
Last time at Koh Tao I stayed and dived with the nice people at Big Blue Diving – question is should I (we – Benjamin and I) stay there again or maybe try some of the other dive places? Koh Tao is full of them…