Though I am sure the advice given in this forum is good, how many of us can afford or justify paying out £100+ for a front light, that we may only use several times a year on reasonably roads that may have stretches with no street lights.
It does depend on what you are going to use your bike and lighting for.
I commute year round, which means I'll spend a good 2-3 months commuting one way or the other in the dark. I also use my bike for shopping and transport in the evenings, not to mention riding audaxes and night rides that require lighting for significant periods of time. I'll add that there aren't that many street lights out here either, and Cumbrian roads are not exactly billiard table smooth.
I've tried cree torches, which are bright and fine until the vibration gets to them and the electrics start getting shaky. I also have a Smart Lunar 35 which is ok if you brake on descents and an Ixon IQ which is pretty good, if a little fragile. The Cyo is reliable, fixed to the bike so I can't forget to pick it up, doesn't run out of battery power and can be run at full power all night without worrying about whether the light will last the night. That is why I'd recommend a dynamo and a good dynamo light.
For others who just need to make the last few miles of a club run, or commute along lit routes most of the time then their requirements may be different, as always YMMV.