It's decent, sometimes great. Fun in many parts, scandalous in many parts.
It's no Cambodia, and it's not as good of a tourist destination as most of the other Southeast Asian countries, but it'll do...
Always make sure the meters are on in the taxi. If they won't turn them on, get out and get another taxi. If you're going by Tuk-Tuk, negotiate the price beforehand. If it sounds sketchy or "more than a few dollars American" don't take it.
Don't use hotels near the railroad station or tracks, inclduding Park View, Bangkok Hotel, Rex Hotel.
Make sure to eat the local TOM KHA.
The Grand Palace is not closed even if locals tell you it is, it's a great place to go, just watch out for scammers selling stuff.
Drink local THAI ICED TEA and realize you can never go back from that moment.
Go to the Chatuchak Weekend Market on Sat or Sun.. it's like 30 acres and thousands of booths and you can find crazy foods there.
Southeast Asia is simply the best place in the world and you can be assured you will have an amazing time.