6th Gen Your most valuable pokemon?

[TwilightBlade]

If strictly speaking about X and Y...

I got a Ditto from the Friend Safari that had 4 perfect IVs. I've caught about 35 Ditto at that point, but I think it's still very rare. 2 IVs are guaranteed perfect while the chances of getting the other 2 perfects are 1/1024. Ditto helped a lot with the breeding prior to getting Pokebank.

I also consider my shiny hatched (non-masuda method) Pumpkaboo to be very rare. I got it through unconventional means. I was doing the egg trick to check a baby's IV inheritance in this guide here so I hatched a shiny Magikarp at first. Based on what I read on other forums, I took my chances in exchanging it for another shiny. I soft reset the game and switched out the daycare parents. Out comes shiny Pumpkaboo. I love it to bits. It's useful in using Frisk + Thief and farming for items in the Friend Safari. I don't want to evolve it.

 

[USC Yuuka]

My most valued Pokemon was my Gardevoir named Luna back in Pokemon Emerald, who made her way all the way to Pokemon Black. But then my DS and Pokemon Black&Emerald were stolen. And so was Luna... Q-Q

In Pokemon X, it would be my Gardevoir named Olivia. Must fill the hole in my chest uwu

 

[Plumpyfoof]

I've transferred all of my in-game teams since Ruby into XY. That entire box of Pokemon is super special to me. My in game teams are the only Pokemon I nicknamed and I haven't levelled them or changed their move-sets since they completed their journey. All except for Gex my Sceptile who I gave some new moves in Black and wow do I regret it.

 

[Hawk Tartaros]

My perfect Timid Jolteon, it's my first 6 IV bred pokemon and it's one of the fastest pokemon out there.

 

[BeachBoy]

Hawlucha, which single-wingedly kept my X nuzlocke alive.

 

[Magica]

I don't really have a single Pokemon I value over another. Well, aside from my shiny Mismagius. But I never use it, I keep it boxed. I guess I'm just weird like that.

 

[J the Gamer]

My genesect keldeo rayquaza and my "special" Dragonite(he is precious to me)

 

[Lapras120]

Mine would either have to be lapras or pidegot.

 

[EagleVision1999]

I feel very attached to my Chimecho. The last few gens I always had one in my team. It had perfect IVs even though I catched it in the wild.

 

[PokeHunterBlack]

probably my sceptile lv 100, in emarald, being my oldest pokemon and my first to get to level 100 with a moveset of
LeafBlade
solarbeam
dragonclaw
fury cutter

it worked great with a groudon i cought and got to lv 80, but then my uncle needed them to beat red in soul silver... and then sarted a new game... sob:(

He was my only friend

 

[Reshiram643]

My most valuable pokemon is my 4iv timid movie event Japanese darkria 2014.

Nice. Japanese events are really rare.

 

[Rosehip]

My shiny Krookodile. It was my very first Wonder Traded Pokemon, WT'd to me as a shiny Sandile. It's currently Level...93, I think? It's so valuable to me because it's my first owned shiny Pokemon besides the standard shiny Gyarados.

 

[HelenBaby]

I actually have a whole bunch of those 10ANNIV Pokémon. Won't say how I got them ^^;

The Pokémon that are most valuable to me are the ones I raised honestly and poured hours into. My lvl 100 Infernape Tommy and lvl 100 Gyrados Davine are the first that spring to mind...

 

[J the Gamer]

Mine would be my shiny mew or my genesect (I sadly traded it for the mew even though it was kinda like my starter in Pokemon black 2 because I got it at the beginning

 

[Centipede Chan]

Right now it has to be the shiny Metagross I got today from someone here (Aeroblast I think it was). Metagross is a cool pokemon and even though we'll be getting an event shiny Beldum for ORAS, this will be competitive made already.