VLC is certainly one of the greatest media players around, but some people have been noticing an annoyance in which it "rebuilds the font cache" nearly every time you start it up. Here's how to disable that behaviour.
Rebuilding the font cache not only takes time, sometimes it can make VLC hang completely, which can get old quickly. To make it stop, just open up VLC and go to Tools > Preferences. Hit the "All" radio button in the bottom left hand corner, then go to Video > Subtitles/OSD in the left-hand pane. In the Text Rendering Module dropdown, pick "Dummy Font Renderer Function" and hit save. The next time you open VLC, you should be free of that annoying cache-building dialog.