Series: Yay or Nay? How Long's Too Long?

I like series (even though I'm never sure of the most grammatically correct way of writing it).

This probably can be traced back to the days when I first started reading fantasy books and (thanks to a resurgence of Tolkien due to The Lord of the Rings movies) everything was in trilogy format. I started to love trilogies because of that. When I graduated from D&D tie in novels, (though I still have a few favorite authors in that universe that I will read, repeatedly) I still paid more attention to trilogies and series.

For me, this is because I feel a character can be better developed over the course of a series than just one novel. Of course, this doesn't take into consideration those endless series that will suffer from Author Existence Failure. Besides, I haven't a clue where to start with those long series...

For me, a perfect length series is somewhere between the three books of a trilogy and six or seven books. Even now, after having read many good stand alone novels, I still tend to gravitate more towards series.

Am I the only one? I do hear many complaints about how all the new books are part of a series, do you like this? Are you a fan of series books? Why? Are you like me and prefer to get out before you're staring at several dozen volumes, or do you like those series?