My Wynaut. *hugs* He was my very first level 100 that wasn't caught on the coast of Cinnabar Island (if we're counting that or anything raised on Missingno.-cloned Rare Candies, my first level 100 was a Golbat), he has a grand total of 60 ribbons (yes, 60!), he's dominated all manner of Pokémon Contest, he's helped me through the Mt. Battle challenge, he's taken on the Tower Tycoon in Sinnoh, and in HeartGold, he was the Pikachu to my Ash- I had him following me outside his Poké Ball all the time. He's over 10 years old by now, and still with me, along with most of his original teammates- Shiftry, Linoone, Swampert, and Castform. It'd be awesome if Pelipper was still with me, but alas, the poor bird never made it past Emerald...
I remember hatching Wynaut's Egg in Slateport City, an entire decade ago. He held an Everstone from birth to that fateful moment when he hit level 99, and my Linoone decided to pick up a Rare Candy after that exact battle. That Candy's what got him to level 100. :)
The Wynaut that I got from Mirage Island. A few misc Pokemon I got from trades with people I've known well. The Blaziken I named after a good friend of mine that I've since gone separate ways from (also technically my oldest Pokemon). The Pokemon traded to me by my SO when we played B/W together.
"Murder of the living is tragic, but murder of the idea is unforgivable." - Janus, speaker of the synod
My Salamence, transferred it to every game since Ruby as part of my main team. He's helped me through every Battle Frontier, Battle Subway and most recently the PWT, it doesn't matter that his IVs are below average, he's far too precious to me to ever consider replacing.