Sensible answers only please.

I am a 28 year old English guy. I have got some savings behind me due to a *fairly* successful self-employed career, which I am now bored of. Around 3M baht.

I intend to go to Bangkok (for my 6th time) but I want to study Thai language. I am prepared to knuckle down hard for a year or maybe more. I already have a fairly basic grasp of the language, am able to recite the alphabet etc etc.., but am not very confident in conversation.

Which is the best place for me to study? I would prefer central Bangkok.

Many many thanks in advance for helpful answers.

If you have the time, the money and are ready to study hard, I would recommend the Intensive Thai Program at Chulalongkorn:

Google: intensive thai chula

With 3m baht I suggest living out of Bangkok would be better. You would still have money left after a year.l

Search on the forum for the Chula intensive Thai and read those reviews. I haven't taken it, but it will force you to know the alphabet and read quickly. Later courses are too reading-oriented for many people, I gather, so after the beginner and maybe the intermediate courses there you might switch to a more conversation-oriented school at a higher level. But that would allow you to power past the very basics at other places, where you'll be stuck using the roman script for a long time.

Learn to read as quickly as possible. It will open up the world to you, and enable you to learn on your own 24 hours a day -- reading menus and signs and the instructions that come with your toaster oven. Until you learn to read, you're stuck learning only from whatever hastily-compiled textbook the school forces upon you.