UPDATE: There’s now a Chrome extension called TheOne which does this, so you don’t need to create your own user script.
I wrote earlier about why it’s wrong for websites to force links to open in a new tab or window, but it’ll probably be at least a few years before the majority of clients and web developers finally come around. In the mean time it’d be nice for users to have a way to prevent their browsers from implementing the practice, but surprisingly there aren’t any Chrome extensions. You can create and install a user script, though.
Here’s my modified version of the script:
// @name Open Links in Same Tab/Window
// @description Prevents websites from forcing links to open in new tabs or windows.
// @version 0.1
var a = document.getElementsByTagName(“a”);
for( i=0; i < a.length; i++ ) if( a[i].target == "_blank" ) a[i].target = "_self"; [/sourcecode]