I ride in the dark a lot so I always use lights. I have many lights. Chinese LEDs are much improved over the past two years, especially if you stay away from the ultra-cheap versions. My most used headlight is probably the $60 Revtronic (formerly Nitefighter) BT40s:
http://www.amazon.com/Revtronic-BT40...ords=revtronic

It's a claimed 1,600 lumens, probably more like 1,400 actually. The beam is noticeably warm which is much more pleasant to look at than a cool tint for hours. the light's not specifically designed for the road but it works fine on both the road and trail. The beam pattern is wide with plenty of throw. The stock battery is very high quality. The light will last four or five hours easily if you don't set it on high (which is too much light for the road anyway).

I also really like the Bontrager Ion, Cygolite and Cateye lights. The Cygolite Expilion 800 in particular is a terrific light for $100. The Cygolite mount is my personal favorite light mount, it's rock solid and simple to use.

For taillights, I avoid ultra-bright flashers if I'm riding in a group. A bright, flashing taillight gets really annoying to those following. I like cheap battery lights like the PDW Red Planet for group rides. I leave them on steady state in a group. If I'm riding alone, I have a number of very bright lights like the Superflash Turbo and Danger Zone.