Our children all go to bed at the same time, and share a room (except the baby who sleeps with dp and me). The older ones tend to stay awake longer, talking, but they are all in bed. ETA: They really look forward to this time at night. We tried having later nights for the older ones, but all of them were unhappy with this arrangement, so we made adjustments to what we're happy with when they are all in bed a the same time. It's a bedtime vs lights-out situation, although they do have the lights out from the first.
Dp and I each have a series that we are reading to them, and we read books by choice during the day. Occasionally when they want a break from the series, dp or I will read a short story instead, at bedtime, and I have opted to read stand-alone books between series'. We choose classic stories that have something to offer all levels of comprehension. We have never done the book-after-book thing at bedtimes, but began reading series' at bedtime when our first two were still babies.
We have read The Chronicles of Narnia, The Lord of the Rings, the Eragon series (minus the book not yet released), The Time series (A Wrinkle in Time- though I couldn't complete the series because it was so poorly written that I grew weary of editing while I read aloud), and I'm on a nearly-finished break from Lemony Snicket presently. I have read many books that narrate real-life adventures in the wilderness, and some very silly books too. The original Winnie the Pooh books (ours is a single volume) would be a nice light read while dp is reading something relatively heavy/dense (like LOTR). Alice in Wonderland and Through the Looking Glass, The Wizard of Oz and Swiss Family Robinson were some early bedtime books we read and will likely re-read as well.
I feel free to leave out racial/religious epithets (and to replace them with salutory descriptors) sometimes found in older classics.
When there is a wiggly baby involved, I nurse while reading, or just hold the baby in my lap while s/he plays with a toy and listens.
We have had to make adjustments at various stages of dynamics between and within the children, but overall, this has been the wonderful and usual routine at bedtime.
After this baby was born and my dp had nightshifts, I was sometimes unable to read at bedtime, so our eldest offered to tell a story instead. After a few nights, we had to institute a rule that the story mustn't go over an hour in length.
Anyway, I cannot imagine trying to have separate bedtime routines at all, but I have closely spaced children, and several of them, so it goes with the territory, I think. It does take some time and a lot of patience from everyone, for the newest ones to learn the expectations of reading-time at bedtime, but they do.
