We need kinetic weapons. Extremely high-velocity solid penetrators.
Also, I\'d love to see Space Hulks - massive, derelict conglomerations of ships infested with aliens. Would be even better if first-person combat ever becomes a thing (for boarding actions and such.
Laser weapons. Either pulse or continuous beam. Laser should be the diameter of the emitter (i.e. if the laser is 3x3x10, the beam should be 3x3