I just add new DVDs to my collection at the end, with only arranging alphabetically for each shelf. I keep track of the DVDs by using tags for each shelves. This way I know in which shelf to look and inside that it will be alphabetical.

Previously I sorted my collection completely alphabetically but with over 1000 DVDs it was a lot of rearranging work each time.

I have mine alphabetically on a bookshelf. New DVDs are piled up beside for a while until I decide to have a filing session.

I have two numeric ranges, one from 1 to 999 and one from 1001 to ...

1 to 999 (currently 537) are my movies sorted alphabetically. 1001 to ... (currently 1172) are my TV shows sorted alphabetically.

So when you sort by number you have my movies first and then my TV shows and within each sorted alphabetically.

I have 3 sections... 2 done alphabetically 1 by when I bought it...

Alphabetically:
Watched Movies
Watched TV Shows

by Purchase Date:
Unwatched DVDs

ok, thx so far - I got some ideas from your answers. I'm now trying to expand my shelf to allow me an easier sorting.

Maybe some have more ideas - but thanks for all who posted their way of sorting.

By genre, for the most part.

i do collection number by date purchased, renumbering each time i sell an older disc, so the disc thats been on the shelf the longest is 1 etc... 

as for my on shelf sorting... its gotten quite out of control as now my collection has expanded from just my room to my living room as well...

Living Room Shelving
Watched HD-DVDs - Alphabetical
Unwatched HD-DVDs - Purchase Date
Unwatched Movies in Snapper Cases - Purchase Date
Unwatched Superbit Movies - Purchase Date
Unwatched Steelbook Cased Movies - Purchase Date

Main Room Shelving
Watched TV Sets - Alphabetical
Unwatched TV Sets - Alphabetical
Movies That I Own for Collectible Reasons Only (will never again watch due to owning a newer version) - Random Order on Top Shelf
Watched Stand-Up Comedy - Alphabetical by Comedian's Last Name
Unwatched Stand-Up Comedy - Purchase Date
Holiday Movies (All Holidays / Watched and Unwatched) - Alphabetical
Animated Movies (Watched and Unwatched) - Alphabetical
Walt Disney Animated Classics (Watched and Unwatched) - Production Year starting with Snow White
Walt Disney Treasures (Watched and Unwatched) - Alphabetical
Watched Movies - Alphabetical
Unwatched Movies - Purchase Date
Watched Blu-Ray Discs - Alphabetical
Unwatched Blu-Ray Discs - Purchase Date


you know what... it sounds more crazy when i type it out like that....

Originally all mine were sorted alphabetically on the shelves with space for growth, but when I outgrew the shelves, with no room to add new ones and books and DVDs all over the place, I started filing into large capacity file folders leaving room for growth but now all that room is gone so now I just add to the end. (I still have a shelving space problem with my books!)
Everything is sorted alphabetically within the profiler and when I do file into the folders those are sorted so while it may look like a mess there is some order. I have a general idea where each disc is stored based on whether it is a movie or a series  - I spilt those initially. My collection number tells me exactly where to find the disc (folder number, page within the folder (each has 40 pages) and then slot number(there are 8 per page)). I currently have 8 folders, each holding 320 discs and 6 are full, with the 3rd series folder having around 70 slots left available and the 5th movies folder still relatively empty with only 7 pages being full.
This makes for one helluva lot of discs (around 2220 actual) and minimal storage space and still a little room for growth   - my wish list would unfortunately fill it and then some!