One of the best (simple) designs I came across was published in
the Design Ideas section of EDN Magazine June 27, 2002, by
Vasiliy Borodai, titled 'Circuit improves further on first-event detector'.
http://www.edn.com/contents/images/62702di.pdf
The circuit requires only two wires per button (three if the LEDs are
placed at the buttons). The signal at the junction of the LED and the
first and second gates could be buffered to drive additional indicator
LEDs, or high power lights for an audience.
Disconnecting one of the inputs of the second gates and wiring them all
together in a common line to an 1M Ohm pull down (fig a) or pull up (fig b)
resistor and a 'Reset' switch to pull this line up or down. This 'Reset'
switch can then be used to 'clear' or 're-arm' the circuit quickly if one of
the players 'jumped the gun'.