1. Flamethrower: This is a powerful Fire-type move with 90 base power and 100% accuracy. It is a reliable choice for taking down opponents that are weak to Fire-type attacks.
2. Solar Beam: This is a Grass-type move with 120 base power, but it takes 2 turns to charge before it can be used. However, it is incredibly powerful and can be devastating against opponents that are weak to Grass-type attacks.
3. Air Slash: This is a Flying-type move with 75 base power and 95% accuracy. It is a good option for hitting opponents from a distance, and it has a high chance of critical hits.
4. Dragon Claw: This is a Dragon-type move with 80 base power and 100% accuracy. It is a good choice for taking down opponents that are weak to Dragon-type attacks.
5. Blast Burn: This is Charizard's signature move, and it is a powerful Fire-type move with 150 base power. However, it can only be used once per battle and has a 50% chance of causing confusion to Charizard.
The best move for Charizard will vary depending on the situation, but these are some of its strongest and most reliable options.