Heinlein and Harris on the one side, and Keyes, Kinsella, and Kellerman on the other (with a few Herbert and Henderson and Koontz and King in between) these take up three or four shelves by themselves. And tomorrow or Monday I'll be working on Lackey and McKinley and McCaffrey. That will take up a lot of space.
I'm not a fanatic about alphabetization; as long as Asimov and Anthony are adjacent, they don't have to come ANthony before ASimov. Since I have limited space, this saves my brain from the trauma of splitting authors between shelves. I hate that. I don't mind too much if there's a natural break - say Lackey's Valdemar series on one shelf and her Bardic Voices on another - but just splitting up the middle of a series bothers me. We all have our little quirks. Similarly, I have hardbacks separate from the other books for the most part. For instance, I have an omnibus volume of the original Dragonriders' series, and it's out here with classic science-fiction hard backs, where the rest of the books (in mass-market paperback) are in my room. Trade size paperbacks mess up my system pretty badly, but I can usually work around them with creative stacking.
ETA: Okay, done through L. Missing the three books of Lackey's Arrows trilogy (part of the larger Valdemar universe). I've re-read them recently, so I know they're around here somewhere. I just left a space big enough for them. And a space for the third book in the Girl with the Dragon Tattoo series; I like them but not enough to buy in hard back.
Why yes, I am a little OCD about this. Why do you ask?