For those that want the modern equivalent to relive your old time crisis, HOD, op-wolf days, (e.g. for mame cabinets), apparently the ones that use a dedicated

For those that want the modern equivalent to relive your old time crisis, HOD, op-wolf days, (e.g. for mame cabinets), apparently the ones that use a dedicated infrared sensor (like the wii) are the most accurate (e.g. www.arcadeguns.com).