Any light emitter isn't going to be that good because of the background lighting where you commute and the limited amount of wattage on a bicycle. Every car will have two or four halogen headlights totalling well over 100 watts and with huge internal reflectors - hard to stand out in that crowd. Your best bet is still put on the brightest and blinkiest lights you can find (I like the Cat Eye products) but especially go all out with reflectors and reflective material. With the reflectors you get to use all the wattage the cars are putting out for free.

Reflectors on the pedals and spokes are outstanding at getting attention and scream bicycle. Reflective vests, leg and arm bands, reflective tape anywhere it will fit, even a reflective bike flag if you can find one. If you've got a rear fender cover the back of it in reflective tape too.