I’ve been using this for a while, but I only realized it’s one of those things I can’t live without when I actually had to go without it for a few minutes earlier…
To turn on this setting, open up Tab Mix Plus Options, click on Events and then the Tab Features tab. You’ll see a checkbox titled “Ctrl-Tab displays a tab list popup menu” which you’ll want to select.
Just try it for a while… if you use as many tabs as I do, you’ll want to always keep this setting on.