Please use y'all. Y'all who don't use it don't know what y'all are missing.
shouldn't this be "don't know what y'all is missing"?
Also acceptable is "what y'all're" or "what-y'all're".
Edit" also "t'y'all're". Note that many of these sound much better said then they look written.
Please use y'all. Y'all who don't use it don't know what y'all are missing.