Your least favourite skins characters?

I arrived late to the party and have watched all of Skins in a very short sitting and therefore have missed most of the discussion on an episode-by-episode basis.

Looking around online there are plenty of discussion posts based around the 'best' of skins. These posts always make for good discussion but I have found almost no discussion around the 'worst' of skins.

So, who are your least favourite characters to appear in the main line-up of skins in any of the 3 generations and what is it that make them less favourable?