Misdreavus
Before Nasty Plot it was the it was the most used Pokemon, had the ability to run several sets each of which was not just powerful but extremely hard to stop (SubSS@LO, SubSalac sometimes with a boosting move, OranCM, even that damn bulky status/trick set). To a large extent it overshadowed three otherwise extremely viable Ghosts, this is not a problem in itself but it is a demonstration of Misdreavus's power.
Misdreavus has not much more raw power than other common sweepers, but it does have several key things which I believe make it at least worth testing.
1. Bulk
65/65/85 base defences are not going to wall many things, but without hitting SE (or some high power STAB moves) its very hard to 1KO. Cranidos's EQ does only ~76%, and that's from the highest base attack in Little Cup. Munchlax's Pursuit is only a 2KO, and against Oran its a 3KO.
For comparison, Chinchou with max def and SpD hits:
24/13/15
while a min/min Misdreavus gets:
22/12/15
For a highly threatening sweeper with 19 Speed and 18 SpA, that is impressive.
2. Brilliant type
Pure ghost with levitate grants three important immunity's (Ground, Fighting and Normal) and two less helpful resistances (Bug and Poison) but with only two weaknesses (Dark which is rare outside Sucker Punch and Ghost, you outspeed and can 1KO most of the common users of Ghost moves). This means that it there are many opportunities to bring missy in, and even if you bring it in on the wrong move you generally have enough bulk to survive.
3. Boosting
With Charge Beam and Calm Mind it was a serious threat and very capable of sweeping once your opponents priority was depleted, but Nast Plot brings it to another level. No more can Munchlax switch in and at least hurt you a lot, now it just dies. No more can you rely on SE/AT Gligar to take a Shadow Ball and weaken you significantly, then speed tie next turn. Misdreavus hits the same special attack after one Nasty Plot as Clamperl (if missy uses Life Orb its much more), combined with much better coverage, significantly better overall defences and 19 Speed (or if you feel like using Salac Berry, 27 Speed).
4. All the coverage it needs
Shadow Ball is a must, and HP Fighting hits almost all that resists it for Super Effective damage. Then you have Charge Beam for if you want to boost while KOing something (and hit Normal/Flyings harder), Psychic, Shadow Sneak and Thunderbolt. It also has a pretty wide support movepool: Thunder Wave, W-o-W, Trick, Pain Split, Memento, Destiny Bond, and Substirute stand out.
However, it does have a case of 4ms syndrome. Luckily it can fit what it needs onto one set, normally two coverage moves one boosting and substitute.
Gligar
Most of my thoughts on Gligar can be found
Here. Despite me argueing largely against banning, I still think it deserves to be tested and voted on. Gligar is a large part of the metagame, perhaps too large.
I would also be for retesting
Clamperl, with the number of protect users and water immunities running around a good player should be able to outstall Trick Room, and it agility pass is a lot of effort to go to. All in all it seems like a special version of Cubone, which is
clearly broken right now.
Meditite could be retested, but I strongly suspect it would quickly be proven too powerful. It has a nutty 32 unboosted attack, and unlike Cubone/Clamperl can hold either an attack boosting item or Choice Scarf. It has a lovely movepool consisting of several STAB options (Psycho Cut, Brick Break, Hi Jump Kick, Zen Headbutt, Focus Punch), the Elemental Punches, and two Priority attacks (Fake Out and Bullet Punch). Along with them it has an array of fun tricks it could pull use to mess with you, Like Substitute, both screens, Counter, Dynamicpunch (with Gravity), Rock Slide, Trick, Drain Punch, even Bulk up and Batton Pass.
Still, its most likely the scarf set that will mess with things the most (and maybe a Croagunkesque priority set). Imagine a Cranidos with more attack, take away Head Smash and Rock Polish, now give it dual STAB, now give it better defences, now give it a workable defensive type (pure rock is horrible), now give it all the elemental Punches, now give it dual priority.. then you pretty much get Meditate.
Murkrow was banned for a reason, it could revenge kill a vast majority of LC Pokemon comfortably, and was exceptionally hard to revenge kill itself. It was a huge centralising force. Especially with talk of banning Gligar, retesting Murkrow seems pointless.
While its true Yanma did not get a proper long test, not did Scyther and no one is asking for that to be brought back. Nor did most of the lv. 100 Ubers. Yanma is part of the 20 speed group, but canget away with not investing at all thanks to its ability to boost its speed. In LC that free speed boost is crazy, especially with halfway decent base 75 SpA and Bug Buzz/Air Slash/Hidden Power available. Hypnosis is just the icing on the cake, though now that its less accurate.. well I'm pretty neutral on Yanma testing.
Edit: I don't think this is a true nomination thread franky, more to get our ideas out about what we may want to test.