Well i give you my best 3 Broadsiders:
Cut-Off

It's a full energy ship. So what's the best tactic against a Full Energy Ship? Cannons and Electro-Bolts!
Use against it These Weapons.
Broadsword

The good old Broadsword is still handing a Hand over in any broadsider battle.
Tough against a non Broadsider it still need's assistance especially against These that are the same or more Design Worthy, because 1 side = Half the Design Price.
Torpedo Salvo

It's a COMPLETE supporter ship, it cant maintenant main fire at itself, so it Needs a Company to be safe.
It's Shooting a whole salvo at the very beginning, though it's no match against a well protected Point Defense Ship.