Madden NFL 08

This is a little bit harder than the pass, but still pretty easy. Just get pass your own 20 yard line (40 yard line for the 60 yard run), and run it to the outside on the left. A good play is the strong toss to the left. Three good running backs for this is Landainian Tomlinson, Willie Parker, and Ronnie Brown.
from 360achievements.org

Similar to the 90 Yard Pass achievement. First bump all your stats up to 100 and the CPU down to zero. U will have 100 % rushing and the CPU will have horrible rush defense and tackling. On your first offensive play go with the quarterback sneak and run the ball back to your 10 yard line and allow yourself to get sacked. I tried it from the 15 yard line and it didn't register. Now on your second play, go with a HB Toss to the more open side of the field. Achievement will unlock at the end of the play if you pass 80 yards. It may take a few tries to register.

So there's a real easy way to do this. Use two controllers. Starting the profile who is getting the achievement from behind their own 15 (just to be safe), select your HB toss, doesn't matter which side. Snap the ball with the first controller, and with the second controller, hold the opposite direction of the play and keep tapping B to switch to the nearest player. This keeps the defense from getting near your ball carrier. If you didn't press anything besides A to snap the ball on the first controller, the computer should run for you. For what it's worth, I unlocked both the 60 and 80 yard achievements at the same time.