Gifts are not taxable income no matter how much you get and are not reported on an income tax return.
If your parents are not US citizens or residents of the US, there are no US tax implications for them.
If you, as a US person, receive a gift of more than $100,000 from a foreign person, you are required to submit a Form 3520 to the IRS. Form 3520 is an informational form only. You do not report a gift received on your personal tax return, regardless of the amount received.
IRS Form 3520 - http://www.irs.gov/pub/irs-pdf/f3520.pdf
IRS Form 3520 instructions - http://www.irs.gov/pub/irs-pdf/i3520.pdf
http://www.irs.gov/Businesses/Gifts-from-Foreign-Person
