Since the nominations end today, I'm going to attempt to nominate Gligar again, this time with more proof.
First of all, let's take a look at its stats at lvl 5, with 236 HP/236 Spd EV spread, and a Jolly nature:
HP 26
ATK 14
DEF 17
SPA 9
SPD 13
SPD 19
The first thing you notice is how high Gligar's overall stats are compared to the rest of LC. Every one of its stats is above 13, except for Sp atk (which you won't be using anyway). 14 ATK is excellent for no investment (I bet some people put 236 ATK EVS, giving it 17 ATK), and it is one of the most defensively bulky pokemon in LC with 17 defense, again with no investment. No big deal, you can pummel it with special attacks ,right? Wrong. The Pre evolution stone gives it 25 Def and 19 Spdef, making it even harder to take down.
And unlike most super bulky pokemon, like Shieldon or Duskull, it can actually hit back. A STAB Earthquake, Aqua Tail, and Stone Edge easily kill most LC pokemon. 19 Speed makes it one of the fastest pokemon in LC, only outspeed by Elekid and Diglett, to my knowledge. Elekid is pwned by Earthquake, and Diglett dies to a constrict from a Tentacool, so those are out of the question. The other common 19 speed pokemon are Staryu, Ponyta, Misdreavus, and Murkrow (maybe not common, but I've used them on my team before), and their defenses pale in comparison to Gligar.
Gligar is so versatile it isn't funny. Need a wall? Get Gligar. Need a choice sweeper? Get Gligar. Need a revenge killer, or a counter to 50% of LC? Gligar's your scorpion. You have no idea what the Gligar you are facing has until it uses a couple moves, and the opponent can change up EVs, allowing it to be an essential part of any team.
Not only are its defenses high, it even gets to Roost first to heal off what little damage you did to it, and remove its flying type for a turn. Unless you do more that 50% damage, and are faster than it, it is insanley hard to take down Gligar. Ground/Flying is one of the best typings defensively, being only weak to Ice and Water, Immune to Electric and Ground, and resistant against fighting, poison, and bug. The ice weakness isn't so bad, because Roost nearly always go first, due to its high speed. Aqua Jet and Ice Shard do nothing off of its 25 Def, and it is able to heal off the damage you did with Roost. For example, my Phanpy did 43% damage with Ice Shard, while the opponent just spammed Roost.
Maybe it's extreme bulkiness is due to the Pre evolution stone, but Gamefreak might have just as well released an item that boosts pre evos att and sp att by 50%.
I've been talking most about defenses so far, but Gligar can kill a bunch of things too, especially with a choice band set. I'm pretty sure that Ground/Rock/Water is unresisted in LC, giving it excellent coverage. 19 speed is really helpful, making it kill many pokemon without even being touched. Why use a pokemon that has to rely on choice items when you can use Gligar?
Gligar has no counters, except for maybe a pokemon with choice scarf and ice beam. And it can just switch out, kill the "counter", and then sweep the rest of your team with Gligar. I'd like for someone to try to name a pokemon that can easily counter Gligar, and do more than just counter it. Bronzor is a decent check, but what can it do back, reflect it away?
No other pokemon has the speed, power, and defenses of Gligar in LC. I've heard a lot of talk about banning Zuruggu, but from my experience Gligar is 3x more common, and a lot more threatening. Zuruggu has to use Dragon Dance to actually do damage, while Gligar already has everything it needs. I'm not saying that Zuruggu is bad, because it sweeps everything with a dragon dance, but Gligar doesn't need to waste a turn preparing. Therefore, I nominate Gligar to be tested.