Sorry for the length.
DPP Aerodactyl Lead ("Bulkier", if you can say that of Aerodactyl)
Aerodactyl@Babiri Berry
144 HP / 12 Def / 136 Spe / 216 SpD
Jolly
-Taunt
-Stealth Rock
-Rock Slide
-Earthquake
Aerodactyl rose up in the ranks as a lead due to his blazing speed, being the fastest Stealth Rocker in OU. In the old metagame, Aerodactyl would easily get a Taunt and a Stealth Rock in. Today, Aerodactyl is still one of the most reliable leads for getting Stealth Rock, but one lead in particular threatens to strip even this title away from him: Scarf Jirachi, who has a 60% chance of shutting down Stealth Rock.
The old Aerodactyl lead ran the simple EVs of 252Atk / 252 Spe, under the following assumptions: Aerodactyl cannot be KO’d before he shuts down Stealth Rock and gets his own up. Now, with Metagross using Bullet Punch, Scarf Jirachi, and other specialty leads including Infernape and Empoleon, these assumptions are somewhat compromised.
The premise of this moveset has not changed: Aerodactyl’s main two moves are Taunt and Stealth Rock. Rock Slide is generally preferred for STAB and so Aerodactyl can try to be Jirachi. The last move is up for grabs: Earthquake handles Infernape, Metagross and Jirachi in a pinch. Ice Fang hits Hippowdon, although this is generally the inferior option since Ice Fang doesn’t hurt Hippowdon much anyways.
These EVs are designed to protect Aerodactyl from today’s lead metagame. With 136 speed and a jolly nature, Aerodactyl reaches 363 speed, which outruns Azelf. The 144 HP and the 216 SpD EVs guarantee that Aerodactyl is not 2HKO’d by Azelf’s Psychic, barring critical hits and special defense drops. Unfortunately, the defensive EVs makes Aerodactyl lose its ability to outrun Scarf-Breloom, though Breloom should not Spore anyways, fearing a Taunt. Babiri Berry is used over Focus Sash because with the fall of leads like Gengar and Gyarados and the rise of Fake Out leads, Sash is becoming less useful.
This Aerodactyl is optimally used in conjunction with Magnezone. Magnezone can assure that Steel-type leads, such as Metagross and Azelf, are trapped and beaten before they can get Stealth Rock up. If Magnezone carries Hidden Power Grass, it can also beat Swampert by coming in on a predicted Ice Beam. Scizor, often used to revenge kill Aerodactyl, is also trapped and killed.
The 4th moveslot can really be used for anything. Aerodactyl can set up either Rain Dance or Sunny Day, although switching Babiri Berry for Damp Rock/Heat Rock takes away from Aerodactyl’s survivability. Protect can be used to scout moves, especially against Jirachi. However, Protect is most commonly found to protect against anti-sash Fake Outs, which this Aerodactyl does not carry. Ice Fang can be used to hit Roserade, Breloom, and Hippowdon for super-effective damage, but generally, Earthquake is the superior option.
As of July, the top 10 leads were: Azelf, Metagross, Jirachi, Swampert, Aerodactyl, Infernape, Hippowdon, Ninjask, Bronzong, Roserade. Aerodactyl does pretty well against these guys.
Azelf: Aerodactyl, who is 3HKO’d, can Taunt to shut down rocks, then Stealth Rock, then Rock Slide so Azelf can’t count on his sash. If Azelf tried to Stealth Rock first turn, then you get two turns of Rock Slide.
Metagross: Aerodactyl taunts, then Stealth Rocks. Due to Babiri Berry, Aerodactyl still has time to get an Earthquake off unless Metagross carries Meteor Mash. Afterwards, Aerodactyl can switch to Magnezone on a predicted Steel attack.
Jirachi: The best thing to do here is to attempt a Stealth Rock. If Jirachi used Iron Head and flinched, Magnezone can switch in easily, and Aerodactyl can use his blinding speed to set up rocks later. If Jirachi used Iron Head and did not flinch, Magnezone can still switch in, except that Stealth Rocks are out, and Aerodactyl can be used as a revenge killer in a pinch, or death fodder.
Swampert: Aerodactyl can Taunt, then set up Stealth Rock. Many Pokemon can come in on predicted Ice Beams and KO.
Aerodactyl: Because of the defensive spread, this Aerodactyl will always lose the speed tie. The best thing to try is to attempt to set up Stealth Rock and hope the other Aerodactyl did not Taunt (usually a safe bet).
Infernape: Aerodactyl can taunt and set up Stealth Rock, followed by an Earthquake to break the sash. Most Leadape are not capable of beating Aerodactyl.
Hippowdon: Aerodactyl taunts then sets up Stealth Rock. Most Hippowdon carry Earthquake+Stealth Rock+Slack Off+Roar, so Aerodactyl is safe. Ice Fang and Stone Edge variants cannot OHKO, barring critical hits.
Ninjask: Taunt shuts down Ninjask, and Aerodactyl can Steath Rock on a predicted Protect.
Bronzong: Taunt shuts down Bronzong, and Gyro Ball does not KO due to Babiri Berry. Magnezone can clean up non-Shed Shell variants. A SubRise version is best for handling Bronzong since Bronzong commonly carries Earthquake.
Roserade: Taunt stops non-Scarf Roserades from using Sleep Powder and Toxic Spikes.