The people, the culture, the views, the food and the markets. Nothing in Thailand is bad. Everything is simply amazing.
Here i'm going to talk about a few high lights!
River Kwai bridge
This is the famous bridge built in ww2 constructed by Japanese soldiers for transport purposes. It is now known as 'death bridge' however, it does house amazing views and a strong history every Australian, and the world should learn about. Walk across, and soak it up.
Khoe Phing Kan
In other words? James Bond Island! Yes, filmed here! Not only this, but the location offers swimming, hikes, markets, and snorkelling off the island. If you're staying in Phuket - this is a must!
Patong Beach
Famous for it's night life being rowdy and anything goes. Patong is also home to beautiful beaches, places to lunch, massages on the beach among other things.
From your hotel here, you can book tours our to the islands, for elephant rides or day trips to see various other animals.

Patong beach sign, Thailand. 2013
These are just a few of many suggestions I have for Thailand. I back packed in 2013 with one of my best friends and it was honestly one of the best trips of my life. We had a ball.
If you'd like a part 2, or a story, please read and share.
Cheers,
Cj. xx