where do you live karim_sie?
and how many other times do you expect to fly on TG?

If you live in Europe but don't fly much, I'd put points into BMI Diamond Club.
If you live in Thailand and fly often, I'd put points into TG
If you live in Europe, and fly often in BUSINESS CLASS, M&M *might* be worth it at a squeeze.

If you don't fly often, you won't gain status in any program, so you might as well go for the local carrier to you in case you can get an upgrade on check-in for example.

If you fly Business Class, go for BD if you don't do it "now and again" (so you get the 200% points and easier chance to mage gold status); LH if you do it very often (so you get 200% points and have the chance to qualify for LH status), and forget Thai altogether if you don't live in Thailand or fly into there regularly.