Phuket is actually the reason I got certified 4 years ago.
My sister was working overseas at the time and we thought Thailand would be a great place for us to meet up and we both wanted to try scuba diving.
So she got certified in Kuwait, I was certified here in Ontario. We met up in Bangkok after my lengthy 36 hour flight (long story about why so long) in the middle of the market square in downtown Bangkok.
We spent 2 days in Bangkok before travelling up to Chiang Mai, one of the Northerly cities & the most tourist known for it's shopping. We did some trek's up the mountains, visited some temples, attended Thai cooking school, and went to many manufacturing warehouses. After a few days in Chiang Mai, we flew to Phuket where we spent our next 5 days on a liveaboard.
Phuket was amazing. We had an average of 100ft of vis every day. We did 4-5 dives/day, and we saw a lot of marine life.
On our liveaboard we met some teenagers from Norway who's uncle worked at the Thai embassy. After our 5 days out at sea, they invited us to their house for a few days to experience the true Thai culture in Phuket.
Needless to say, this is a trip I'll never forget. The people, the culture and the amusing antics of the locals will never be replaced.