Try a Vivitar 283 or 285 as either are possibly some of the most versatile flashes ever made. The 283 is a bit cheaper as it doesn't include the zoom or swivel head or manual flash power modes of the 285, but in any of the 4 auto modes either are so easy to use and nearly always very effective. Just choose the auto mode for the distance your working with (look on the dial on the side e.g the yellow mode for the longest distance away, the purple for the shortest), and set the lens to the relevant aperture for the films ISO and the mode your using (get this from the dial on the side), and then within the range displayed anything will be correctly exposed including when bouncing. As its an auto type flash which works from the light sensor on the front, it will work with any camera, and you'll be surprised how effective this is.
If what I am saying makes no sense then the manual can be found here, which explains it quite well:
http://www.cameramanuals.org/flashes_meters/vivitar_283_larger.pdf
Theres a 283 going quite cheap on ebay at the minute, they usually go for ~£20 and 285s for about double that.
http://www.ebay.co.uk/itm/VIVITAR-2...ories_CameraFlashUnits_JN&hash=item3a88927bcf