I just love Gold duck..he is definitely my favorite..
While octillery seems to get a lot of love in Japan here in the states it's mostly forgotten. It has poor speed and defenses, yes, but amazing attack and special attack and a giant movepool. With a little set-up it can be amazing. Trick room makes it a fast sweeper and with sniper the occasional critical hit becomes a OHKO. Its vast movepool can let it hit just about anything for super effective damage on either physical or special side and an expert belt can fake a choice set giving a free KO. Suction cups makes it an amazing baton pass reciever without worry of being phazed out. Volbeat (another underrated pokemon) can pass a couple tail glow boosts giving octillery more power than it could ever need, or have a pokemon pass an agility or two and watch as the enemy team falls before the octopus. Moody is banned in most competitive circles and for good reason. With a little luck there is nothing that can stand up to octillery. Overall a great pokemon with a great design and a unique style of evolution that focuses on the theme rather than the animal, the revolver becomes a tank.
Dunsparce. Though I've noticed Mystery Dungeon's touch in making unloved Pokemon loved, such as Grovyle, Sunflora, and Chatot.
But I think Gardevoir, battle wise anyhow. If you search it up on google all you get is a bunch of disgusting garbage and it really angers me. I've loved Gardevoir since I first raised mine in Sapphire, but a lot of people think Gardevoir is awful in battling. Now that its a Fairy type, it's even stronger! Combine a Power band to lower it's speed, raise it's special defense, teach it trick room, and it could be a real power house with Psychic and a Psychic gem. It can even learn Destiny bond if you breed right.
Darmanitan, but get rid of it's checks and it's open season for that thing to set up a Hone Claws sweep. It's surprisingly easy the amount of things that are weak to that thing. Pack up a Lum Berry, and you get a free Hone Claws boost to whatever tries to burn you. @_@
Along with the above, I've recently discovered how underrated Azumarill is. Especially Subpunch Azu. People would initially think that it's banded, and they get a nasty surprise in Focus Punch. It's the perfect check for Subpetaya Empoleon, since Focus Punch wrecks it too, I believe. Aqua Jet is also perfect for picking off weakened Heracross, or weakening it so it can be revenge killed by one of your teammates. Crazy stuff.
Ledian. Freaking cute as hell, and I love his Comet Punch attack.
Yeah, you can tell I like Bug Types.
Pokemon player since 2003, Wikia member since 2013, Zerahead fan since 2011, Pokemon master (ish) since 2004
Electric friend safari with Electabuzz, Luxio and Emolga
After doing my run-throughs at the Battle Maison, I can honestly say that Golurk is a bit underrated. Mine has No Guard, which has gotten me wins in a pinch and on top of that, he's survived hits that should have killed him.
Claimed: Golett ~ Iron Fist ~ Shadow Punch ~ Big Pearl ~ Light Clay.
delphox is underrated for me because he is in ru and yet he is a lot stronger than chesnaught who is in uu because chesnaught doesn't get a good move until level 32