Although, Thailand has hundreds of islands in the Gulf of Thailand and also in the Andaman Sea, it is rather difficult to choose a few out of them to give you the best islands in Thailand. All Islands in Thailand are good however, it depends on what kind of holidays you're looking for.
The list of islands that are famous in 2014 are:
Koh Kood - One of the Best Islands in Thailand
The eastern most island of Thailand. It's a great place to chill out and relax with the family and enjoy the crystal clear water. This place is much more suited for a family trip to give a sense of togetherness as it's quite and seems close to nature. Get on a boat from Trat city for an hour and you can be in this beautiful island. This island have few bars on the beach and few resorts as well
Koh Chang - Famous Among Expats and Tourists
Koh Chang is next to Koh Kood and it's definitely a mix of everything. In Koh Chang you can find beaches that are quite
and not touristy, but if you want to enjoy the nightlife they've beaches for that as well. Famous beaches are Lonely beach and Bang Bao beach.
They've have quite a lot of accommodations available in Koh Chang and depends completely on your budget. They have it starting from somewhere around $10 to more than $150.
Another great island in Thailand is Koh Similan. It is a group of islands in the south of Thailand in the gulf coast in the famous district Koh Phangan, Thailand. Koh Similan is getting more popular nowadays because of the activities it offers which are suited for a family traveling to Thailand and also to a traveler traveling alone. It has 9 islands in total but Koh Similan is the largest and the most famous one.
Activities in Koh Similan include Snorkeling and Scuba Diving. The highlight of this place is it's amazing coral growth and huge boulders which are unlike to find in the islands of South in Phuket
Koh lipe is more traditional as it has Sea gypsies living in the east side of the island. The island doesn't have any cars and the only way of transportation is from a motorbike or long-tail boats which can take you from one place of the island to another in return for some money.
Lots of Hotels are available in Koh Lipe
and the price range is quite reasonable as well. Highlights for Koh Lipe island would be it's Free diving in the Sunrise beach, Snorkeling, Massaging and Kayaking.
Just few km away from the industrial city of Thailand. You can get to Koh Samed by a speed boat which might be pricey or by a boat which could cost somewhere between $2-$3 and takes around an hour to be there.
Some beaches are famous for it's nightlife and some for it's quietness. If you're looking to party then Sai Kaew Beach is famous for it's parties on the beach. Aoi noi Na is famous for it's beauty and it's way quieter than the other ones. Motorbikes could be easily rented in Koh Samed with just one 7-eleven available you should make sure you have al the things available with you.
Koh Larn is an island located about 30 minutes away from the famous Pattaya City. It's definitely quiter than Pattaya with some breathtaking views. If you're looking for fun in Pattaya city then this island is a "must go" island.
Even though it's touristy but you can still feel the vibe of being in the middle of no where and enjoy the beach. There are lots of hotels available and thy might be a little pricey here because of the tourists, but if you're not willing to pay that much then I would recommend you to take the boat back to Pattaya and get a cheap hotel
for somewhere around $17 or more.