I'd like to see some kind of mine that takes 30 cargo space, is only allowed to be mounted on fighters, fast fire rate,(basically, takes ammo, and each ammo takes 30 cargo space, so you can only buy 2 ammo) and to use it, just fire it twice(so that it'll take a fighter shield down then the hull). It has a massive effective radius and tracks the ship that launched it instantly. It's essentially a kamikaze mine, and can take out a squadron of fighters, however it should mount on the shield slot so that fighters with it are very easy to kill, and it takes a lot of energy, so fighters with it are only for this purpose.
I've always wanted an option to load your ship with explosives and run into an enemy. The mine should have a relatively small radius though, so you can't just drop it and run.
The ammo should be cheap, but the launcher should cost about 5 mil or so, to bring it inline with the supernova. It should only insta kill fighters though, maybe take down a gunboat's shields. It would obviously be available only for terrorists and maybe AI's though.