This is a lead Claydol set that I tested out. It certainly exceeded my expectations.
Trick Claydol Lead
Claydol @ Choice Scarf
Nature: Timid
EVs: 184 HP / 216 Spe / 110 SpA
~ Earth Power / Psychic / Ice Beam
~ Rapid Spin
~ Stealth Rock
~ Trick
I wanted a lead that could both rapid spin and set up its own rocks. Out of Armaldo, Donphan, Forretress, Kabutops, Sandslash and Torkoal, Claydol stood out for trick, its bulk, levitate, and resistance to stealth rock. Also trick is not TOO commonly seen on Claydol (which is not commonly seen itself).
The given EVs put Claydol at 396 scarfed speed, enough to beat +nature base 130s such as Aerodactyl. This is extremely important as it allows Claydol to easily shut down many stealth rock leads by either locking them into taunt or rocks, then spinning them away.
110 SpA attack EVs let Claydol to always 2hko 4 HP Jirachi, 252 HP non-shuca Metagross, shuca Heatran, and Infernape.
Earth Power v.s. 4 HP/0 SDef
Jirachi : 171-201 Damage, 50-59%. 100% chance to 2HKO
Earth Power v.s. 252 HP/0 SDef
Metagross : 186-219 Damage, 51-60%. 100% chance to 2HKO
Earth Power v.s. 4 HP/0 SDef
Heatran : 326-383 Damage, 100%. 100% chance to 1HKO, 2HKO with shuca berry.
You can also use 252 HP/60 Def instead of 110 SpA for greater usage later in the game.
Here's how it fares against the top 20 leads of September:
1. Azelf: Trick it, if it taunts then switch out, if it sets up rocks then spin/set up rocks.
2. Metagross: Trick it, then spin/set up rocks/earth power.
3. Jirachi: Stealth rock as it tricks, then gain switch advantage, spin the turn after, (Scarf Jirachi is faster, it sets up stealth rock, then you spin.) or 2HKO with earth power.
4. Aerodactyl: Trick it as it taunts, then switch.
5. Swampert: Trick it.
6. Smeargle: I suggest absorbing sleep with another poke, since smeargle sets up hazards which claydol can then spin away.
7. Infernape: You can go with a fast earth power, or trick.
8.
Roserade: This is a problem. Claydol has no easy way to best roserade as both leaf storm and sleep powder causes problems.
9.
Ninjask: This is another problem. The best you can do is switch out or set up rocks.
10. Heatran: You can earth power for a 2hko on shuca, or trick.
11. Hippowdon: Trick it.
12.
Tyranitar: Probably better off tricking it.
13.
Crobat: You can go for a quick stealth rock, since crobat will probably hypnosis.
14. Bronzong: Bronzong can't do anything but hypnosis, which can be problematic. You either can switch out, or trick and hope hypnosis misses.
15. Gliscor: Trick it as it taunts.
16. Ambipom: Set up rocks.
17. Forretress: Trick.
18.
Mamoswine: You probably want to trick it, but ice shard is a 2hko.
19.
Abomasnow: If you're feeling really lucky you can trick it and hope it substitutes/leech seeds, or Blizzard gets a minimum damage roll. (283 SpA Blizzard does 88-100%) Stealth rock is really good to get off against hail teams.
20.
Empoleon: Not too much you can do, switch out. Hydro pump 1hkos.
Nothing really stops Claydol from getting up rocks, only a few things can 1HKO it (Roserade, Abomasnow sometimes, Empoleon) and quite a few things are crippled by trick.