I recently picked up a Yongnuo YN-560 II flash, at the suggestion of Scott Kelby. I am impressed, this flash has a very good build and creates great light. The controls are easy to use (wish my Canon’s were this easy) and I can use it as a slave flash (which is why I got it).
In this image the Yongnuo YN-560 II is in a Ziser Zumbrella camera right at 1/64 power. Camera was a 1D Mark III using the excellent 100mm f/2 lens. Aperture f/2.2 at 1/125 and ISO 200.
I am very impressed with this flash. They have increased in price $10 since I got mine but they are still under $80 at Amazon.
I have seen comments that they don’t hold up over time but even a Canon flash won’t if you treat it roughly. Only time will tell.
If you need a flash and shoot in manual (no ETTL with this unit) then check out the Yongnuo YN-560 II, at these prices you can get 2!