There are so many options in the aftermarket for gauges, it's hard to pick what will look good on your dashboard. Analog vs. digital. 52mm vs 67mm. Dark face vs. light face. Post pictures here of your gauges and tell us why you picked them.
Just to get this thread started with some pictures - I'm stealing a quote from another thread with some awesome custom work by MetalMan:
Autometer Ultralite 67mm mechanical boost and electrical oil temp gauges set in Cravenspeed flexpod for R53.
Alta gauge packages : boost / water Dont buy these. The pods are cheap plastic and the gauges arent the greatest... usually difficult to read. They do match perfectly at night and thus look great at night however. Do something like BThayer did above.
Craven Bracket "W" with dual gauge pods / Marshall gauges. More larger images in my Garage (just click on "MY Garage" icon on left.