Headphone amplifier - Use a FiiO amp inline with my headphones to improve the quality of the sound a little bit. I find the amp makes the surround sound effect work better with bass tones (gun shots, explosions etc).
Modmic - Not a well known solution to the headset problem but one I really like. Take any pair of decent headphones and add a mic to them directly with a magnetic attachment to the headphones. Solves the age old problem of rubbish mic combined with rubbish headphones sold overpriced to gamers.