If you like using an alternate site to watch YouTube videos (like the minimalist Tube, which we recently covered, or the more minimalist Surprise.ly, which we covered long ago, then you can set up a Chrome extension to redirect you every time you click on a YouTube link.
To redirect YouTube videos to Tube, install the Redirector Chrome extension. Open the extension from the Chrome toolbar, click "Create new redirect," and fill it out like this:
(The 1234 is just a placeholder; you could type a different random string there. The * is a wildcard, and the $US1 ($1) means you want to keep the video ID from the original URL.)
Hit save, and you're done.
You can set up a similar redirect with Surprise.ly, or with any other YouTube viewer. And of course you can use this extension to redirect any kind of URL to any other kind of URL.
If you don't like dealing with wildcards and variables, try Requestly instead, which lets you just name the part of the URL you always want to change, without requiring wildcards.