Claydol

Claydol has a few very good movesets available to it, and is one of the few Pokemon blessed with optimal dual-STAB movesets. Without a doubt, it has the moveset to make for a large offensive threat, but its stats just don't allow it to shine like it wants to. That said, it's not all bad for poor Claydol; it's a decent defender with a variable moveset that can keep attackers guessing to a degree, though anything that resists both Psychic and Ground really doesn't see it as much of a threat.

Best PvE Offensive Moveset

• Confusion edges out Extrasensory, but they perform similarly.
• Psychic should be paired with the above for a full Psychic-type set.
• Mud Slap and Scorching Sands make for Claydol's most optimal Ground-type set.
• Earthquake is not far behind Earth Power in general, but it's still not quite worth considering.
• Gyro Ball has no offensive use.
• Shadow Ball is powerful, but lacks STAB.
• Ice Beam doesn't suit Claydol's role. 
• Rock Tomb is even worse. 

Best PvE Defensive Moveset

• Confusion and Mud Slap are the best general choices, though the former is neutrally stronger.
• Extrasensory is entirely outclassed on defense.
• Psychic and Ice Beam are preferred for their relatively early damage windows and 2 bars. 
• Shadow Ball is largely unresisted in general, but is relatively easy to dodge. 
• Earth Power and Gyro Ball are very slow for 2-bar moves, and the latter's coverage isn't particularly valuable either. 
• Scorching Sands is on a par with Earth Power, trading a bit of power for a harder dodge window.
• Rock Tomb performs similarly bad on defense.
• Earthquake is unviable for defense.

Confusion is the preferred fast move. While Extrasensory does have a slight advantage over Confusion, it falls significantly behind in raw damage. 

All of Claydol's Charge Moves are moderately costly in terms of energy, making Claydol rather slow with shield pressure. Earth Power and Psychic benefit from STAB to deal strong damage, though the latter might provide redundant coverage due to Claydol's fast move. Scorching Sands is very competitive with Earth Power, as it has a lower energy cost and a chance to debuff Attack, but slightly lower power as a trade-off. Shadow Ball is a powerful option that is largely unresisted against the meta, but lacks STAB. Ice Beam provides useful coverage, including against Claydol's weakness to Grass Pokemon. Gyro Ball is a poor move and doesn't provide enough damage for its energy cost, nor is its coverage considered valuable in general. Earthquake demands the most amount of energy, discouraging its use. The addition of Rock Tomb following the GBL Season 10 update is unimpressive, as its poor damage output and high energy cost discourages its use despite its new debuff utility.