A lot of people would agree with you. Lady Chatterley was my "first" Lawrence, and so I have very fond memories of it. I also love a lot of his short stories. In my MA program, the professor who taught Lawrence was a brilliant and gorgeous woman. She focused on Lady Chatterley, also, in her British Lit class -- felt that novel was more accessible and that it was easier for students new to Lawrence to see his distinction between a life of nature (romance) and an industrial/technological life of reduced humanity.

There is nothing like the experiance of the first Lawrence book. If that was the case, then yes, Lady is indeed a fine choice, and I would certainly consider it at the top of your Lawrence list.
Cheers, Translator