It depends on what you want. If you want a fast physical sweeper, you would choose Mega Aerodactyl. However, if you want a simple all-out attacker, my choice would be Rampardos. If you want a wall, then Bastiodon is the only way to go. My choice would be Aerodactyl, because who cares about defense when you hit first and kill the enemy? :)
Moveset:
Aerodactyl @ Aerodactylite
Ability: Pressure
EVs: 40 HP / 252 Atk / 216 Spe
Jolly Nature
- Stealth Rock
- Taunt
- Stone Edge
- Earthquake