Thank you
Thank you, very much appreciated.

Could you suggest alternative sentences to express my appreciation?

thanks!!

Question

Thank you
Thank you, very much appreciated.

Could you suggest alternative sentences to express my appreciation?

thanks!!

Answer

Perhaps:  'I'm very/most/extremely grateful (+ to + person) (+ for + object)

eg I'm extremely grateful for all your help
     I'm very grateful to everyone who helped.

Or use the verb 'appreciate'

eg I really appreciate all the help you've given me on this project

The phrase 'Much obliged' exists, but it can sound a bit dismissive.

NB avoid using the word 'thankful'. It isn't a synonym of 'grateful', as it has a slightly different meaning.

Answer

Even more naturally, you could say, "Thanks, I (really) appreciate it." or "Thank you very much."