Spoon

I think this is one of the areas where you basically get what you pay for. Unless you want to make your own guages then buy the best that you can afford normally Carbtune or Davida. Don't think theres much difference between dials and column types apart from maybe columns being easier to read. I've heard that cheap guages can lack accuracy which is obviously not good.

I've got a set of Carbtune guages that I've had for years. They've paid for themselves many many times over and I would buy them again in a shot.