Kung Fu Panda Real pandas are pretty bad at kung fu, so the alternative would be to get a guy in a panda suit, which might be amusing but would probably scare the kids in the audience.
Cars The talking-car genre reached its live-action peak with KITT on Knight Rider, who, incidentally, would probably be a strong addition to the animated Cars franchise.
The Iron Giant This heartfelt story about a sensitive alien robot that bonds with a young boy during the 1950s would probably end up looking like a Transformers spin-off if a studio attempted a live-action version.
The Emperor’s New Groove This madcap, Looney Tunes-influenced comedy (featuring a main character who gets transformed into a llama) would never work if constrained by real actors and locations.
The Secret of NIMH Oh wait, it was recently announced that this story of experimentally enhanced rats who’ve escaped from a lab would be getting a live-action remake. Thanks, Hollywood.