Many years ago I went with a 23" barrel on a rifle because I couldn't decide between 22" and 24". I was very happy with it. Back then everybody seemed to be chopping their barrels back to 21" or 20" or even less.
I felt like an odd man out. I am happy to see so much agreement on this thread that 23" can be a very good choice for many situations.
Another odd length: I made up a semi-heavy varmint rifle and since weight wasn't too much of a consideration, I went with a 25" barrel on it. I have been very happy with that one, too.
For me, handling and balance are very important. A 23" barrel length in today's common barrel contours usually works out quite well.