Series books?

Okay, I've come to the conclusion, you're either a series person or you're not. Some readers love to revisit old characters while reading a book while others don't.  I've come to the conclusion as an author, I love writing series. But it can be a challenge. When I sit down to write on of my Doms of Chicago books, it's like coming home to a pair of warm fuzzy slippers, but in the long run it's also the hardest, because I have to remember to put enough background information in the following books that if a reader picks up one of the books in the middle of the series they can easily pick up the storyline and not be lost.  Nothing is more frustrating than reading a book, not realizing it's a middle book of a series and then being lost.  So it's a pitfall all us authors have to remember when we're writing. 

So what about when reading? I read just as much if not more than I write.  I'm a true book-aholic.  And as such a I love series books, because if they're done right, I fall in love and then the author ends up on my auto-buy list because I want to see what's going on.  So what series do you love to read?  I have several I'm reading over various genres.  Below is what is currently on my e-reader. (there are tons more than this that I do follow, but come on my Kindle can only hold so many books. 

• Anitra Lynn McLeod - Seven Brothers for McBride (a sci-fi, vampire, m/m series)
• Eve Langlais - Freakin' Series (paranormal m/f shapeshifters)
• Sean Michael - Hammer Series (bdsm, m/m series)
• Karen Mercury - How the West Was Done Series (m/m/f western, historical series) 
• Laurann Dohner - New Species Series (m/f shapeshifter series)

and of course I can't forget my all time favorite series...which I'm waiting impatiently for the author to add more new releases. I swear she can't write them fast enough to please me. 

• Marie Harte's  Circ's Recruits, Dawn Endeavor and  PowerUp series.