Here's one:
Team A trailing 10-9. 4:00 left in 4th quarter.
3rd and 10 on the 11.
Team A gains 9 yards on the play, down to the 2, but is face masked (doesn't matter which one).
Options:
4th and 1 at the 2. (Decline penalty)
1st and Goal at the 1 (Accept penalty)
1st and 1 at the 2. (Accept penalty but not yardage)
To eat the clock, I would rather take the last option, so I could sit on the ball twice, try to get a first down on third down, get a new series, sit on the ball three times again, then kick a field goal with no time remaining.