Even thought I saw Fellowship of the Ring before I had read the books, I still see the Uruk-hai as these cartoon-y creatures; in fact, they look just like these brown aliens from an episode of that (thankfully) short-lived Buzz Lightyear show...

And Ents are just tree trunks that are broken at the top and have arms.
Also, in my mind, Wormtongue is a little, white, naked (but lacking genitalia) guy who looks a lot like a wrinkly version of the aliens from
Close Encounters (though his eyes aren't quite that big).
And the fall of Sauron is infinitely cooler than the way Peter Jackson did it...oh, wait, that's the way it's
supposed to be...