Lost. I liked the show but hated Jack and most of the other main characters. Tertiary characters like Daniel Faraday were much more interesting.
I LOVED--like fanatically-obsessed-crazy loved--LOST, but Jack & Kate were the most boring characters of the bunch. I liked Locke, Sayid, Ben, Hurley, etc, but the Jack/Kate/Sawyer triangle was the most annoying, dull and downright frustrating part of the show. Sawyer at least had some very funny lines. Jack & Kate---no. They were just annoying and whiny.