> Save yourself the headache and make a <script> tag with an id

That's not always efficient. Suppose you want the same lengthy template to be available across several pages which share the same JavaScript. Then it makes a lot more sense to put the template in the JS and serve it once than to put it in the DOM and serve it repeatedly. Also, with the DOM approach, you have to insert data into the template using regex rather than simple str1 + data + str2.

If syntax highlighting is really your major concern, write a simple script that compiles your .html to .coffee (sandwiched with """). Best of both worlds.