As Shirley says, the red led gerber infinity ultra is very good,
You might want to try the Dorcy Hawkeye (I think)_ which has a luxeon emitter powered by three AAA cells and holds two filters in the hilt, one red and one blue, it seems pretty good to me.
Apparently niteize are making the minimag drop in led modules in all colours soon, watch out for them.
Not to mention, stylus,peaks,inova keychains,photons,fauxtons from lighthound,surefire filters,petzl headlamps, cheap bicycle tail lights, etc etc
etc.
Recommended though for all round toughness and durability is the INOVA X5 with red leds...sweet.