I'm sure over the games you've played there are some Pokémon you've held on to through the generations that you like to use in battles every now and then some of mine are Pipy the Empoleon from my first ever playthrough of Pokémon Platinum, Guzma the shiny Golisopod that I was bored enough to hunt one day, Beri the shiny Butterfree who is my second ever shiny and this shiny Salamence named 'I can Fly' that I got in a trade so what are some of your favourite Pokémon you like to use? and what do you like best about them?
I have just a couple that I like to use on a team if I can, the first is a male slaking named Siadhal, I have a fond memory of it due to me evolving my uncle's vigoroth when I was younger, I also love its ability to be an extremely powerful revenge killer, aka it revenges its friends. The other is a female Absol I have named Disaster, it is a mixed set that is meant to take the opponent by surprise just like natural weather phenomena, also Absol is my favorite Pokémon . Finally I would have to say that using my female Espeon named Atropos is fun, mainly because I spent a literal 24 hours breeding for a HA timid 5iv eevee that was female. It was so worth the effort because of how much I love it!
I really liked using Volcarona in Black! Also, Gyarados is lots of fun — Milotic was amazing in Alpha Sapphire ( he had competitive and faced a horde of intimidate mightyena and promptly slaughtered them with a +5 surf ), and any available dragon-type I can squeeze into my team, honestly.
Throughout almost every single Pokémon game I've played, I've always used an Absol. Absol are glass cannons, sure, but they have a very diverse move pool, from Night Slash to Psycho Cut to X-Scissor and so on. Plus, they've always looked super cool to me.
Just as an add-on, since I forgot to mention in my previous — aside for Volcarona, Haxorus was a huge powerhouse in my Black team, too. I forget his moveset but I remember either SD or DD really kicking up that Dragon Claw up several notches. Camerupt was a champ in my first run of Emerald, if only because I traded my Swampert to a friend and never got him back...
I received her from another person but I have my Shiny Sylveon, he is my baby. It made me fall in love with the shiny for Sylveon since I am a pink person over blue but Sylveon did it XD Also, my espeon, raised her to level 100 and she has been in my Y and AS game on my main team
During ValorBattles, I prefer using my vappy (vaporeon) 'cause it is able to use all the three attacks and I've won all the battles (two) I've played till today.
I'd probably have to go with Nidoking simply because that is literally the only Pokémon I've ever got in more than 2 titles.
In every game it's available, I've loved to sweep everything with a Milotic. It's a bulky hard hitting Pokémon that's very aesthetically pleasing on top of it's battle abilities. Not to mention it's very viable in Contests! So pretty as it wrecks the competition...
There are two Pokémon I keep around, my shiny Haxorus, Blackorus, who unfortunately got traded away by my stupid friend And my Garchomp from Platinum.
Pretty much my whole HeartGold team, although my favorites from there are my Togekiss (Fortunato), which was the first I ever put effort into breeding, my Lucario (Ruko), and my Mew that I got from the 10th anniversary of gold version, which was the first I raised to level 100. It's not for battles, but I also have a Smeargle that I taught moves to in order to make it good at catching Pokémon. There was an event Smeargle like it, so I was inspired to breed my own in Y. Her name's Marie.
I will always love Treecko and use Sceptile whenever I can. In SM I grew very attached to my Decidueye, and I keep it on my time no matter what other mons I catch that could purchase it.
I don't remember the Pokémon I used in RBY and GSC, but I do remember starting with Torchic in RSE and he became my go-to for just about every jam I faced, especially in the Battle Frontier. Then there was my Umbreon in XD : Gale of Darkness. He was such a champ, always tanking and helping capture even late-game, dangerous Pokémon. He never left my team. In DPPt, I was psyched to finally get new Eeveelutions, so as soon as I could get an Eevee I bred an army of them (especially for competitions, though I stopped playing once Stealth Rock became the norm). In HG/SS, I caught a Paras in the Ilex Forest, and he eventually became my go-to for taking on and capturing Mewtwo.
I've got a lot. =) But my top favorites I adore having with me and using are my Diancie and shiny Whimsicott. The latter is so gorgeous shiny and was given to me by a friend, and the former looks great mega evolved so I always love using her.. I'll be moving them up to the new games as they come out and happily keeping them on my team. They're sitting in Bank right now, awaiting USUM's release and when I finish the story there. ۹(˒௰˓)۶ sooonn
Slagros the Umbreon is my homie for life. Ever since Gen 2 I've (almost) always had a male Umbreon named Slagros on my team.