It's not many men could make a forensic examination suit look sexy, is it? :-) Fond as I am of S2 Nick, I think it's fair to say that he's at his most attractive in Series 1. It's the Hair. Not to mention, that certain sassy, casual swagger he seems to have. He's more carefree is S1, not weighed down so much by the knowledge of Helen's affair with Stephen, and the timeline change, and it shows. Not to mention the 'I know I'm right' look!