What model of flash gun am i best getting for macro photography?

I'm getting into macro photography and it suddenly as become apparent that I'm going to need a decent flash gun.
The problem this I'm clueless to what's best for me.
I have a nikon D80 and I plan to photograph insects however I'm on a budget of around £150. Any help will be appreciated.

If you can find a SB-600, you can use it wirelessly with your D80. I do this with my D90, and it works great. Hold the flash fairly close to the subject, flip down the 14mm diffuser thingie, and shoot away. The large flash acts like a giant softbox at that distance.

Me i use the cheapest one i can find, usually off online auctions,

off course you want to go off camera right? Then get a $10/quid flash a trigger and receiver and go for it, that will set you back about 80 quid

Hi, when I shoot macro inside with flash I use the Nikon off camera hot shoe to hot shoe cord (see Nikon'w web site for the one you need) and a Nikon SB-600 as that is what I have. If I was only shooting macro then as you will see on the web site they have other, less expensive flash units that will work with full dedication to fit in with your budget. Off camera at 45 degrees and a white card fill works for a lot of my work. Hope that helps.

Power isn't an issue with macro work - the problem is often too much light from the flash because you are so close to the subject, and the metering system doesn't cope with flash well at 2 inches…
Left on the camera's hot shoe, the position and angle if often such that the light can't be directed at the subject, and if it does hit the target, harsh shadows may result. Better to bounce the light off a piece of white card or similar.

Bouncing gives you just one more thing to manage when you are getting up close and intimate with a bee or spider; times when hands-free would be useful. My suggestion is to buy any flash that will synch with the Nikon - there are plenty of inexpensive options from Nissin, Sigma and others, and second-hand Nikon guns are fine. Don't go for the most powerful and you will find you budget is OK.

Normally IO would counsel to make sure the head can tilt and swivel (both) so that you can bounce the flash of walls and ceilings, no matter how you have to position your camera. But for your macro work, you can get a cheaper fixed head gun and add a ring adapter.

These lightweight devices fit over the flash gun and circle your lens, mimicking the very pricey ring-flash systems which fashion photographers love, but which were designed for macro photographers. They give even, shadowless lighting perfect for close-up work: the lens never casts a shadow on the subject no matter how close you get and your through-the-lens metering works normally. They cost $70 or less on eBay. I use an F170 O0Flash, but there are other brands available.