mmm pizza.
ok Gun answered that one.
best weapon to use against battleships, not that you'll be seeing any for a LONG time, is a well rounded defense...lots of cannon fodder (missle launchers and small lasers), a nice amount of heavy lasers, Ions cannons (less damage than a heavy laser but shields are MUCH stronger), and guass cannons...plasma cannons will be a long way off for most of you. and of course both shield domes.