Only in the event that you already know the recipient should you consider alternatives such as "Kind regards," or "With best wishes," appropriate. If in doubt, stick to "faithfully," or "sincerely,". Also note that in either case, the "Y" of "Yours" is capped, and the "f" or "s" of "faithfully," or "sincerely," respectively is lower_case. Note the comma after both "faithfully," and "sincerely," too. The positioning of the closing phrase differ depending on the format: FBF: Align left, MBF: Align right.
By ensuring that these main elements of a good cover letter format are properly done, you can feel confident that the employer will consider you for the role.