I am biased toward white, but it isn't as easy to keep clean as I thought, looks better between washes than say black, but doesn't exactly not show the dirt, titanium would be better in that respect.

I think titanium silver is a great color on German cars, the issue is that so does everyone else, silver cars are everywhere, but white cars are becoming the new silver lately, so you see more and more white - hard to be unique with either color.

Get a red one - hardly every see a red X5!