Why don't we talk about our most memorable moments from Sun and Moon in anticipation for Ultra Sun and Ultra Moon. For instance, my most memorable moment was just a day after getting my Pokémon Sun and Moon Duel Pack PreOrder, just after getting to Route 2, I ended up catching a Shiny Alolan Meowth, which was also my first ever shiny catch.
My most memorable moment would be when I deposited a Lapras into the GTS asking for a Weavile in return because I gave up on getting the needed item to evolve Sneasel and getting a shiny Weavile a couple days later.
Huh, kinda reminds me of the time I got a shiny Charmander on Wonder Trade in Alpha Sapphire. I traded it for a Reshiram cause I already had a shiny Charizard from GTS... Which in my opinion still needs some work done...
Shiny Pokémon from Wonder Trade is such an awesome surprise. I got a shiny Swampert from Wondet Trade in Omega Ruby which was the second best moment I had in the game. (First was finding shiny Zorua in the wild but this is getting a bit off topic.) Also, I forgot to mention the shiny Weavile was nicknamed Snibunna.
Since everyone is talking about shiny Pokémon for memorable moments... My first shiny Pokémon I encountered in S/M was a Minior while I was searching high and low for a Cleffa. Since I knew straight away Minior could self destruct, I nearly had a heart attack when I tried throwing a quick ball at it and immediately escaped (Turns out you need to bring its shield down to capture the suckers). I thought it was going to be another episode of the shiny Weezing of Stark Mountain... But it didn't. Not once did it use Self Destruct as I chipped down its health until it revealed its black and rainbow speckled radiance. I then I caught it with a dusk ball. I was ecstatic. I named it Black Opal.
Recently, I was Wonder Trading (because I had spent an hour on the GTS and had given up in a fit of incandescent Eren-like rage) and I received a shiny Popplio. The best part was that I didn't think it was shiny at first. I was telling myself 'this isn't shiny, this isn't shiny, so don't get your hopes up' and then I checked out it's summary. She was nicknamed Azura. #MissingNo
I would say for shiny memories, I caught my first shiny because I was trying to help out my team in the summer scramble. I was surprised when I actually managed to capture a shiny Caterpie and I was ecstatic because even if Caterpie's not such a great Pokémon, it's one of my favorites. For game-story related memories, I really enjoyed meeting Red and Blue and the battle tree.
It's not really a good memory, but I do have a memorable moment I'd like to share. I spent a huge portion of the game with a Salandit in my party. Over time it became progressively less useful I really wanted it to evolve. After a long time I finally broke down and looked up how to evolve it and learned that only the females can evolve, meaning that my male Salandit would be pretty much useless be the end-game. I had to go and catch a female and train her up to where the rest of my party was at and evolve her, but I never liked her as much as my first Salandit.