Question

1. I like him because of his honesty.
2. I like him on account of his honesty.
3. I like him on the ground of his honesty.
4. I like him thanks to his honesty.
5. I like him owing to his honesty.
6. I like him due to his honesty.

(Are they all grammatical? Do they have the same meaning? Do you have some more common expressions similiar to 'because of'?)

Answer 1

1-5 are correct, but 3 is not common at all. All mean the same thing.

6 includes an incorrect use of the word "due."
http://grammar.ccc.commnet.edu/grammar/plague.htm
See #7.