I couldn't pick one myself. If eating hadn't been in there I could of cast a vote, but I for one like to eat and think its a little more wholesome than lets say cheating..........I don't know, look at who you are asking!
Lying about cheating or stealing is the most worse of the lot. We all Lie, cheat or steal at least once in our lives. Not saying its acceptable behaviour or anything.
If you look at it, all the other things on the list end up being things you will have to lie to keep covered up, so lying should be at the top of the list (Looking back up, oh it was on top of the list)
And I don't think that means when your wife asked if this dress makes her hips look bigger. Yeah, it may be a lie, but its not trying to cover your tracks on something else.
Cheating is much worse than lying. There may be many good reasons to lie, eg; nice shoes....no Mr. Nazi I'm not Jewish...sure we like your husband...I never noticed your lazy eye...and Don't worry, no one saw, to name a few. Bullshit makes the world go 'round, if you don't believe me ask Hillary.