One of the reasons I like him is because of his laziness. Shikamaru reminds me of myself; being smart, but cynical and too damn lazy to care. That's the reason he's my favorite character. Really, this show is so popular because of Kishimoto's character building. There are more fighting animes than I could count; this one stands apart for a reason.

Though I've read far ahead into the manga, I never liked Neji, Itachi, Tsunade etc. as much as I liked (and still like) Shikamaru.

Eventually these so-called "flavor of the month" fans will move on to another character and the true fans will remain.