I don't have a favorite aspect of bottling. Except emptying them. :<'> That's why I keg - mostly.
There are times when I do bottle though. Bottling is reserved for gifts, to archive a brew, contests or to age that special Barley Wine.
I never seem to have enough bottles. Actually I always have bottles, unfortunately most of them have science projects growing inside. What I try to do now, is rinse them on the washer after the beer is consumed. Later, when I do need to wash them, no surprises inside!
The washer is made from 1/2 and 1/4 inch copper tubing.