On a somewhat prominent /fit/ness forum, they consider the pinnacle of lifting to be 4/3/2/1 plates for the big 4 lifts. The bar is 45 lb. Each plate is 45 lb. This equates to

405 lbs for deadlift

315 lbs for squat

225 lbs for bench press

135 lbs for overhead press

If you can do these weights for these exercises, you are in the top 1% for strength.