Please do not be confused between bar charts (one bar is used to show each quantity of interest) and dynamite plots (one bar shows the average of each group, plus error bars). Dynamite plots are NEVER acceptable because they hide the distribution of the data for no reason at all.

Yes I realize that this is by far the most common type of plot. It is a big problem that reflects the (low) importance that researchers place on the shape of their data. If you were a detective looking for a murder weapon, would it be better if a witness told you 1) only the location and size of the weapon? or 2) the location, size, and shape?

http://biostat.mc.vanderbilt.edu/wiki/pub/Main/TatsukiRcode/Poster3.pdf