Got about 400 now (shop bought) and about 100 (Sky Rip). All the ones shop bought I used to have them via Certificate and then on B/Hol I changed it to Genre, and then on another b/hol etc I changed it to Actor/Actress etc. The ones from Sky just kept them in the disk container.
However, despite me having a good photographic memory my brother & sisters would lend them, but I got too many to be able to control the library (lol) properly and on a few occasions they took them without asking.
So now I have a DVD list on the pc & store them Alphabetical. They are on 4x 6ft Wooden shelves (home made) fitting in-between the chimney wall.
Like someone said, if by Alphabetical I know if someone has taken one without asking.
I don't mind letting sister/brother etc asking, but when they take them that pee's me off, so now they know I will notice if 1 is missing.
I do the Box-Sets 1st and these are on the highest shelf (most value at the time), followed by singles.
I don't collect tv series, just Movies
Another reason for using shelves is to highlight to my sister/brother to show them I can see what I have spent my money on rather (like someone else said) whereas they can't see there drink units consumed lol.