I'm assuming this is over time?
My initial thought is either a clustered chart and let the reader simply "see" the delta, or a line-column chart with actuals and projected as line series, and the delta plotted as a column series (if size of numbers is an issue, perhaps using a percentage would help?). Or, if they are like a typical PHB, and just want pretty colors, perhaps something like this?
http://peltiertech.com/WordPress/two-color-xy-area-combo-chart-guest-post/
If this is for categories, I'd recommend either a clustered bar or a dot plot. The latter is not native to XL, but it can be done...
http://peltiertech.com/Excel/Charts/DotPlot.html