What is the best commuter bike light to purchase?

crayfish asked: When I commute home from work most of the streets are well lit, but there’s one two mile stretch where I bike through a park which has no lighting. Any recommendations on a good bike light? LED versus halogen? Is it worth it to spend $200+ on a good bike [...]

How does the switch on my bike light work?

Stanleymonkey asked: I have an LED headlight on my bike. If I press the switch once it lights up.
If I press it again, it starts flashing – when I press it again it goes off.

How does that switch work? Does it use transistors in a speciall circuit – or is it something else?