Most platings are visibly appealing, but I have concerns about the durability of many of the available platings. Because of these concerns, I ONLY use the following four platings:
Chrome
Yep. they use it on your car bumper and your motorcycle tail pipes. They also use it on pens. It's a very durable and appealing finish that goes with most everything.
Titanium Gold
Titanium Nitride (TiN) has a gold color, and is very hard. My personal pen uses this plating and after many months of constant carrying and daily use, shows no sign of wear.
Black Titanium
Titanium Oxide is an incredibly hard plating. It has a distinctive, sliver-black color unlike anything else. One of my favorites.
Rhodium
Related to platinum, rhodium is very hard and durable, and makes a beautiful pen.