I'll second the recommendation of the B&M Ixon IQ Speed. You can buy it from Peter White Cycles. We use it with a dynamo hub wheel, also built by Peter White. This allows us to recharge not only the light but AA batteries that we use in other devices on the bike. If we run out of charge, we can use a spare set of AA batteries - in a pinch. When we are not concerned about riding for many, many hours, we use the CygoLite MityCross which we feel is brighter. The handlebar lights are supplemented with a DiNotte helmet mounted light.

For rear lights, we always have two chain stay lights. Favorites include the Portland Radbot. Two are important to us because one can lose battery power and leave us underlit. We use the the Di Notte on the seat post (absolutely the brightest tail light). And, for good measure, a Blackburn Flea or something similar on back of helmet.

For riding at night, we always wear reflective vests and reflective ankle straps (there's research that the circular motion of reflective ankle straps really get motorists' attention). The comment about side lighting is important - many accidents at night occur from the side.

We ride a tandem ... lots of money invested in lighting because as randonneurs we ride for many hours throughout the night. I find that with proper lighting we actually get greater respect and distance from passing motorists than when we ride in daylight. We've grown to love night riding.

I'd suggest establishing your budget (bigger the better, but of course not everyone can afford a $1,000 lighting budget) and then focusing on maximizing front and back illumination. Especially for the back, I feel two lights are essential. Fortunately, vests and ankle straps are cheap (I heard that Ikea is selling reflective vests right now for only $4.99).