Hi! I am a TurboTax CPA with over 10 years of experience. The answer to your question depends on how you elected to be taxed. I will briefly describe the two most common ways you could be taxed with an LLC (S-corp and sole prop). If you are taxed as a sole prop, it is a bit of a moot point to file a W-2 for yourself since you are assessed the self-employment tax on the entire amount of your profits and get a deduction for half of the amount for purposes of the income tax. Thank being said, you still may deduct the employer's half of employment taxes on your schedule C. You cannot deduct the employee's half.
For an S-corp, you should file a W-2 for any employee services you render to your business. In this case the FICA taxes for the employer's half of FICA are deductible in preparing the 1120S but since the employee's half is not deductible to the business since they are witheld from your gross wages.
In either event the employee's half of FICA will not be deductible but the employer's will be.