Veph, I loved your screenshot collection. So I had to copy and do my own XD Not quite as professional looking though.
Pre-Stabled!
ZEPHIEL

My only spirit beast. And the only one that Durana will ever need. Each time I look at him, I am so thankful that I managed to tame him. <3
BALAUR

Balaur has stomped his way into my heart. I'm so glad I managed to pick him up with relatively little hassle. It's gonna be a hard choice between him and Zephiel as to who I'll be leveling with in Cata.
HOLLOW

Gotta love the oil covered wolf. I wanted to tame him whilst he was still available, just in case blizz decided to remove his buff. But I'm ahsamed to say I'm not as attached to him as I am with my other pets.
LLIIRA

Aotona makes the last of the sholazar trio, I'm still amazed I got them all. Haven't spent as much time with her as I have with the others, but she's very pretty.
OM

This guy has been with me through thick and thin! We've seen Ragnaros, Hakkar, Onyxia and many other bosses, and he took them on without even blinking. And he's a big derpy turtle, what's not to love?
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Re-tames!
I actually had a bit of a zen feeling when I was going though Azeroth and picking up all my old friends. So many memories of adentured we had, and regrets at having to let them go. I'm so glad I was given the chance to find them all again.
FALRIM

Back in BC, this guy was my main raiding pet. I sadly let him go early on in wrath, I think for Loque'. I'm glad he's back where he belongs now.
Interesting side note; Durana is the only character who is able to get Sian-Rotom to spawn whenever she wants. I have tried with other characters, both alliance and horde, and have had firends try as well. Only Dura seems to be able to get him to appear. Perhaps it ws a sign that he always wanted to come back?
GORIYA

I tamed Mist Howler as a spur-of-the-moment thing... And I fell in love with her. I had to let her go for the oil covered wolf, knowing I would get her back as soon as I could. Sure enough, she was the first re-tame I made. It just feels right having her by my side again.
SHERATON

I do love Warp Stalkers. This guy was with me for most of BC, but I let him go in favour of Om. I get the feeling that he'll be changing colour when Gezz is flagegd tamable again though.
FORGE

Forge was my Wrath raiding pet, before everyone went wolf crazy anyway. I just love his colours, how he moves and the little dangly piece of skin under his chin. <3 (Random I know, but it's true!)
RHAGA

Two devilsaurs! :O This gal was my first Devilsaur tame, back when they rolled out the 3.0 patch in BC. I had to let her go to make stable space, but I'm glad she's back. And she has a big green mate now too. :3
MISSING IN ACTION
A few pets I haven't been able to retame;
TWITCH: Silithid Ravager- Just haven't been luck enough to see him respawn. I know the colour is still around in Cata, but I'd love to snap him up before then.
CRUCIBLE: Ancient Corehound- I would go and get him now, but my brother's accoutn is down so I can't use that to form a raid with. And my friends have gone into hibernation until Cata hits. I will get him back though!
KHARASH: Vilebranch Raiding Worg- Kharash was with me for four years before I had to let him go. I cared about him a lot, and it hurt to have to abandon him. But now, I'm not sure whether to tame him again or not. Why? Well, I'm thinking of making him into a worgen rogue come Cataclysm. I think that'd be a fitting way to keep him about.
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New Pets!
DOMINO

I've always loved this Wind Serpent look. I rememeber looking at it in the model viewer during BC and wishing that it was one of the tamable skins. But alas, never had the space up until now.
LIGEIA

Another case of "Wanted to tame but didn't have the space". Always loved the look of the Jormungar Worms, glad to finally have one with me. She may be changing colours if Blizzard ever introduces some of the new ones in Cata. *Hopes*
And that's that! (whew)
There are a few pets I'll be taming when Cata hits us finally, but this list is long enough already. :3