Buck Henry, 'Grumpy Old Men'

Hapless IRS agent Elliott Snyder (Henry) chases John Gustafson (Jack Lemmon) for $57,000 -- $13,000 plus 11 years of penalties and interest. If Gustafson can't get the money, he'll lose his house. In the end Gustafson's frenemy, played by Walter Matthau, comes through for him, letting Lemmon ride off into the sunset, all paid-up.
Tax takeaway: When you owe back taxes, it pays to have loyal -- if crotchety -- friends.