Conceited people are the worst!

Or greed. Haha, I looked at gluttony and thought 'well, I'm screwed then...' XDDD

Lusting after something leads to most of the others. You get envious, prideful, wrathful, greedy, and you become a glutton. Not necessarily lazy, though.

Greed isn't really that bad on a major scale, Sloth isn't a huge deal, Gluttony isn't that bad on a major scale, Envy is a natural emotion, Pride isn't that bad on a major scale, Lust may be bad but it doesn't start a wars, but Wrath is anger, an even though it is an emotion, it can cause wars.

I agree on what BlondLionEzel said for the most part. Most of the deadly sins aren't really bad on any major levels. In fact most of them seem harmless,Especially Sloth.