Those were the top two that jumped into my head as well. Frankly, anything from Pixar is going to be spectacular, as their blu-rays are always flawless. Finding Nemo is the most visually appealing to me personally, but Wall-E, The Incredibles, Toy Story 3... they all have their moments of jaw-dropping beauty. And it's not just Pixar; animated films in general. Kung Fu Panda, Despicable Me, How to Train Your Dragon, Frozen, Rio, Madagascar 3.... they might not all be good movies, but they look damn impressive.
Honestly, anything that you like that also provides some sense of spectacle is going to be worth watching on a giant screen. The original Star Wars trilogy, Indiana Jones, Pirates of the Caribbean, Die Hard, The Lord of the Rings trilogy... it's all good. I'm a big fan of BBC nature documentaries like Planet Earth, Life and Frozen Planet; bet those look stunning on a big screen.
How big did you go? My wife and I are upgrading from a dying 52" to a 65", so I'll probably be back in a week to pull recommendations out of this thread myself.