What good night headlights?

for commute in city with street light

If the street lights are not good enough for you to see I'd suggest getting something with at least 10w of light. The NightHawk Raptor comes to mind, it can be had for $50 or less.
If the street lighting is good enough for you to see but you just want to have a flasher so others will see you then just about any LED flasher will do the trick to be honest. I'm sure others will both agree and disagree with me.

Absolutely. Lighting is to the Commuter forum what Shimano vs Campy vs SRAM is to the Road forum. Everyone has a different--and strongly held--opinion. Here's mine:

Nearly all my night riding is done on well-lit city streets--generally well-trafficked ones at that.

I found that the inexpensive blinkies are ineffective. They get lost in the constellation of other city lights. Even careful and well meaning drivers have pulled out in front of me when all I had was a CatEye EL-210 blinkie.

When I added a 10W NiteRider TrailRat halogen, it helped tremendously. Still, given the physical size of the light and its brightness/dimness as compared to car headlights, occassionally cars would still misjudge my distance, thinking I was further away than I actually was.

In February I added a DiNotte Ultra 5 high-powered LED light to the others on my bars. THAT changed everything. Running that baby in its "Uzi Burst" strobe mode stops cars dead. I don't know or care what they think I am, but they see me and yield when appropriate. I've had no issues with cars turning in front of me since I got this light.

I've put two of them on my road bike, and run them on constant mode. I get more than adequate light from them and decent respect from drivers.

Others will say nothing less than a HID will do. Riding with HID-equipped cyclists, I think they're too much light for city streets. They're completely overwhelming. Blinding drivers doesn't seem like a very good strategy. This goes double for helmet-mounted HIDs.

+1 for the DiNotte Ultra 5, especially in flash mode. I've got one for my handlebars and the 3 watt version for my helmet. Does well enough to light up the road in the pitch black, though I'll probably augment with a medium power halogen in the winter to get broader coverage. The DiNottes are very small and lightweight.

Even if the streetlights are good enough to see by consider upping your game to substantial lights. I'm a purely urban commuter (always at night one way) and run HID after upgrading from two two 5 LED lights on the front. Advantages: I now have enough light to overcome numerous other sources to make certain traffic is aware of my presence (aimed appropriately they are not blinding). I can actually see into the shadows where a hole might be or a person with nefarious intent. Both of those are serious safety considerations that have come into play a number of times. Get the best lights you can reasonably afford if you're going to be spending any amount of time commuting at night.

Observations on light sources:
Halogen: good light to see, blends in nicely. Looks like a household flashlight from a block.
LED: Really grabs the attention. Poor to see with. Excellent visibility range.
HID: Seizes the advantages of both Halogen and LED but certainly not perfect.

sofor this what you say?
one NiteHawk Raptor on right side, and one Cateye EL530 on left side of handlebars


......

This is definitely true for the vast majority of LED bike lights. These are the kind that run on a couple AAA batteries and contain a cluster of LEDs. The Luxeon 3 and 5 watt bulbs the Dinotte uses are much better for seeing by. They put out around 80-120 lumens and can drop four 2600mAH batteries in about an hour and a half. They've got a very bright, but narrow beam pattern. A friend of mine likes his Blackburn System X6 quite a lot. It comes with two light pods- one with a narrow beam pattern, one with a wide one.

Don't get me wrong--HIDs will still beat the pants off of the best LED. For me though, LED is a great balance of weight, light output, price and power efficiency.

what is luxeon?

Luxeon is a product line of high-output LEDs made by Philips.

https://www.lumileds.com/products/luxeon/