Active lights are far more effective than reflectors. A Planet Bike Superflash can be had for under $20 dollars, and is extremely effective. For headlights, you'll need to decide whether you need a light you can see by, or if you can get by with one that's only intended to be seen. For seeing-by, I used an MC-E flashlight (until it got stolen last month) and was very happy with it. Many people here recommend the Magicshine headlight, which is basically a similar flashlight with a larger battery pack. The downside is that see-by lights generally cost $100 or more, and have battery lives measured in hours. Be-seen lights can be had quite cheaply, and will last for weeks or months between battery charges/replacement.