Generally, Married Filing Jointly (MFJ) will get a family the most tax benefit but if your spouse does not want to file together then you have other options.
Head of Household (HOH) is usually more beneficial for the taxpayer than Married Filing Separately(MFS) because you lose several key tax breaks with MFS.
If you and your spouse lived apart for half of the year and you paid for your own household, then you can do HOH.
You cannot file Single if you were married on 12/31/17.
