What is the best weapon to use for attacking someone are defense?

What is the best weapon to use for attacking someone are defense?
Need some answers about some weapons!

mars on earth is best weapon with antov plane

not really Stationary staff weapon has 900 fire power and it weighs only 500kg well a mars weighs 180000kg and had 850 fire power

Thats not on earth LuckyMan we r talking about on earth not in space

but you can't buy stationary staff weapon on atlantis??

which is the best veicle on space??