I’m not sure he is primarily an inventor. The real invention was the arc reactor, but his daddy did that. Most of what he does is ultra-engineering and uber-optimization.
The Polar Express
Breakheart Pass.
In addition to many of those mentioned, I add: Primer, Cube, Forbidden Planet, The Day the Earth Stood Still, 2001, Silent Running, and Total Recall.
The Train
Unstoppable
Seriously, though, most of the engineers I know seem to have an affection for hard SF, or whatever comes closest to that on film.
Also, Deepwater Horizon seems generally well thought of by the oil industry types I know.
The Dish
I remember that. It was good.
My dad thought *National Lampoon’s Christmas Vacation *was a riot.
The thing the first Iron Man movie got right was the sheer joy of building cool stuff. The sequence where he’s figuring out the suit’s flying mechanism is just gloriously fun.
The aforementioned Primer is high on my list and I’m surprised it’s taken so long to mention Gravity.
Can you be a successful inventor without being an engineer, at least in practical terms?
Bridge on The River Kwai - there is a speech by the young demolitions man as a disgruntled draughty about drawing and redrawing and redrawing that girder, which is why he wants to blow the bridge up [sorry - couldn’t find a clip].
Maybe it doesn’t resonate in a post-CAD world.
I teach Reliability Engineering, and I always cite this movie. Amusingly, the aircraft in the movie is called a “Reindeer.” A few years later, life imitated art when several British “Comet” aircrafts crashed for the same reason. Comet of course being one of the most famous reindeer!
Other movies that trip my engineering trigger: The original Cheaper By The Dozen (not the execrable remake with Steve Martin) and all the *Iron Man *films, plus Army of Darkness where Ash is “inventing” stuff from the future. I also like how *MacGyver *and Burn Notice do similar stuff, but those aren’t movies.
Of course most of my favorite movies are not favorites based on me being an engineer.
Three not mentioned so far (yes, I have an engineering degree):
Brazil - the steampunk Ministry of Information scene cracks me up - he got the technology kind of right (I know it’s a spoof), but how people use said technology is spot on
Twister - one of my favorite movies, seeing the engineering design choices between TOTO and Dorothy, both of which are kind of stupid
Office Space - not the software engineering, but the most accurate depiction of the workspace ever filmed
The Illusionist, The Sting, The Train, Worlds Fastest Indian, Fat Man and Little Boy
Love African Queen - great steam engine, but if they had oxy acetylene tanks for torpedoes, why did the repair the propeller on an open forge?
Crane
Depends what you’re inventing, and more importantly, who you’re collaborating with. Is someone with great ideas that gets other people to make them work an inventor? I certainly think so.
It isn’t an ultralight. They are kites with engines. 
I don’t think an aircraft consisting of about 1/3 of a C-82 would qualify as an ultralight.
XKCD (of course) comments on this very thing.
Nija’d by carniverousplant.
Oh yeah - Horatio’s Drive
Crane