- For Teachers
"take my hat off to you" is, as mentioned elsewhere, a bit dated. It is also not exactly used as "thanks", it is really to show your respect or even surprise for a job well done.
Example: John has just set up a new website, it is excellent and he has done all the design and programming himself. I have to take my hat off to him, he's done a fantastic job.
"much obliged" is fine, a bit neutral but better than a boring "thanks". The other suggestions are just not English (yet!)