I'm not a big fan of Phuket, particularly if you're looking for stunning beaches that aren't crowded. For that, I tend to think of Railay, but to be honest, my favorite Thai beach is still Songkhla.

That said, on Phuket you might have a look at places on Mai Khao beach, which is very long and relatively undeveloped. The resorts here include the JW Marriott, Anantara and Renaissance.

Beyond that, I would suggest that you really need to rethink your day trip destinations. I don't really understand the attraction of a day trip to Phi Phi. Yes, it's pretty, but it's more like a pale version of Phang Nga bay, which is still hands-down the most spectacular place to see in Thailand. Likewise, while I've been on a few very enjoyable week-long scuba diving visits to the Similans, I don't see the attraction of making a day trip there just for snorkeling. It's a long way to go, and given the coral bleaching of the last few years, the shallow reefs probably aren't much to look at.

Given your budget, I would have a look at the Six Senses resort on Koh Yao, which is right in the middle of Phang Nga bay. It would be central to everything except the Similans.

We stayed at the JW Mariott when we went to Phuket in June, and called for cars to bring us around the place (took a boat ride to Krabi, the resort can arrange it for you). We hit $500 a night for a family of four.

Unfortunately, Six Senses is fully booked. Thanks for the valuable information. Any other resorts similar to Six Senses around Phang Nga Bay?

two places---in krabi---amari vogue and sheraton krabi

but my #1 place now is in khao lak---jw marriott

I second the Krabi recommendation - I prefer the Tubkaak, right next to the Amari Vogue, a smaller property, a bit more expensive but worth it.

Hi
Similan Islands is abit far from Phuket but I think it will be fine mostly package included minibus take you from the hotel to the pier.
If you like diving / snorkeling perhaps stay at Khao lak and do liveboard 2 / 3 days to Similan , Surin and Tachai islands.

About Phuket, I suggest serenity resort near the beach ,sea view and nice room at Rawai beach,
here check out their website : http://www.serenityphuket.com/
other discounts sites: http://booking.hoteltrip.com/hotel/10030014-11415104O.html
or this site: http://www.orbitz.com/hotel/Thailand/Phuket/Serenity_Resort_and_Residences_Phuket.h307803/
you can rent a scooter for sightseeing around there and get to Kata Beach, Karon Beach, Patong for night market about 30 mins.

For Krabi I would advice stay at Railay there is good location for the beach, you also can take longtail boatback to Ao nang for foods or nightlife about 10 - 15 mins.

Thanks for all the replies.

Anyone have any views on the Naka Island Starwood resort? I konw it used to be a Six Senses resort awhile back, but the reviews seem all over the place.

Also, anyone have any idea about the Rayavadee?

Thanks in advance for the help!

Rayavadee is a great hotel ,nice location and good service it's quite a huge I mean they have 3 beaches area in Railay , Phra Nang and Nammao beach.
Deluxe Pavilion will close to Railay
Spa Pavilion room will look like Deluxe but have outdoor private jacuzzi.
Hydro Pool Pavilion will have private hydro pool
Have Rai Talay Terrace for lunch and dinner.
Phra Nang will have Beach Bar.
Nammao beach is not place for swimming