I was going to farm all these sets and take screenshots in WoW, but then I realized it would take ages and decided to use ModelViewer. I currently have only two of these sets. Never been a big fan of transmog until now and therefore my "wardrobe" could use some new additions to it.
It took me ages to make this post, don't let the fails in pictures disturb you too much.
My all-time favorite transmog: Merciless Gladiator's Dreadgear. I've been using it for a really long time.
It looks very much like the previous transmog.. but it's GREEN! Take a look at it. Neither gloves nor weapons could be found on Wowhead so I just matched it with [Gloves of the Corruptor], [Skull of Burning Shadows] and [Shard of the Azzinoth].
A blue mix of warlock and priest gear. Despite it looking quite messy and distinctive I like the combination.
[Dark Conjuror's Collar], [Robe of the Shadow Council], [Blood-cursed Shoulderpads], [Saga's Gloves], [Splintering Greatstaff].
A colourful blue set with the awesome demon wings. It's very known and used by locks I know. Love that felhunter's face. Staff: [Zhar'doom, Greatstaff of the Devourer].
I found this priest set when I was looking for a fancy white set that even a warlock could wear. It can be found on this page! This is one of the only xmogs that I have at the moment on my own character. The character in the picture is wearing this staff instead of the weapons mentioned on the site.
To be continued.