Everyone knows about the big sci-fi movies from the 2000s. We're talking about the hits like AvatarA.I: Artificial IntelligenceMinority ReportStar Trek, and District 9. And as wonderful as those films are, they are far from the only great sci-fi movies released in the decade.

The 2000s were actually filled with a whole bunch of hidden gem sci-fi films. The ones that flew under the radar or weren't seen by the audience that they deserved. And that's a shame because these are some of the best pieces of cinema in the decade, regardless of genre. Here are 10 sci-fi masterpieces you may have overlooked from the 2000s.

Altered

A subgenre of science fiction that often gets overlooked is horror. These films expertly blend the stuff we love about the genre with the scares associated with horror. That might be why 2006's Altered is a relatively unknown flick. It was directed by Eduardo Sanchez in his first solo effort since the Blair Witch Project.

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Altered turned a traditional storyline on its head. It focused on a group of humans who abduct an alien as revenge for getting abducted when they were younger. The guys quickly realize how the aliens are far superior. It's gory, cheesy, and B-movie shlock, which is what makes it so endearing.

The Fountain

Tommy engulfed in the explosion of the dying star in The Fountain

The list remains in 2006 with The Fountain. When you look at the incredible talent involved in it, you'll be left scratching your head on why nobody seems to know about it. The film is directed by Academy Award-nominee Darren Aronofsky and stars Hugh Jackman and Rachel Weisz.

The Fountain was told through three storylines, centering around a man and woman bound by love in various time periods. It is a gorgeous and ambitiously crafted film. Sadly, it bombed at the box office, grossing just $16 million on a $35 million budget. Since then, it has become a cult favorite and is a stellar addition to Aronofsky's filmography.

9

Another sci-fi subgenre that doesn't get the love it deserves is animation. Director Shane Acker did a splendid job in putting together one of the best animated sci-fi films of the decade with 9. This 2009 movie was about a rag doll in a postapocalyptic world who could help save humanity.

That's a weird concept on paper, which probably played a factor in the lackluster performance of 9. However, a lot of praise has been given to the art design and the voice acting. Boasting a cast of Elijah Wood, Christopher Plummer, and Jennifer Connelly, it's easy to see why.

Mr. Nobody

Jared Leto has gone on to have one of the most impressive and versatile acting careers of anyone in Hollywood. Pretty good for a guy who also shined as the lead singer for 30 Seconds to Mars. One of Leto's most intriguing roles came as Nemo Nobody in 2009's Mr. Nobody.

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In this film, Nemo is the last mortal human left on Earth after the species discovered quasi-immortality. Leto delivered a tremendous performance and the movie was commended for the cinematography, soundtrack, and nonlinear storytelling techniques. It's a highlight of Leto's fabulous career.

Splice

Vincenzo Natali has shown himself to be one of the most creative names in the world of sci-fi cinema. It started with Cube in 1997 before he went on to direct Cypher and Nothing. But his finest work to date just might be 2009's Splice. The premise isn't all that original, as it involves science experiments gone wrong.

Splice follows a couple (played by Adrien Brody and Sarah Polley) who attempts to inject human DNA into their work splicing animal genes. Their accidental creation, known as Dren, is one of the more unique and interesting characters of the decade. This is a claustrophobic sci-fi horror film that deserved to be seen by more people.

Paprika

2006 was truly a great year for sci-fi movies. That held true across the globe and the Japanese film Paprika is a perfect example of why. This anime thriller is far different from everything else on this list. It took place in a fictional Japan where a device was invented that allowed therapists to enter their patients' dreams

If this sounds like a similar idea to the one popularized in 2010's Inception, then you're right. But this came first and did it just as well. The dream viewing was a rare correct prediction of the future by a sci-fi movie. The animation made it so we could get the full scope of what these dream worlds looked like. Combining those kinds of visuals with a gripping plot is what made this work so well.

Children Of Men

Honestly, it is mind-blowing that Children of Men wasn't a bigger hit. The film had everything going for it. An acclaimed visionary director in Alfonso Cuaron, an outstanding cast led by Clive Owen, and a unique concept. It all looked fantastic when trailers first arrived for it.

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Yet somehow, the film managed to gross just $70 million on a $76 million budget. Based on the novel of the same name, Children of Men took place in a world on the brink of extinction thanks to infertility. Owen's character must help the first pregnant woman in over a decade survive as a crisis threatens their lives.

A Scanner Darkly

We've hit our third and final animated feature on the list. And again, it's a release from 2006. A Scanner Darkly is based on a Philip K. Dick novel of the same name. Directed by Richard Linklater, you'll find that this is one of the most unique looking films ever created.

During a huge drug epidemic in the future, the story centers around deception, surveillance, and identity. A Scanner Darkly is boosted by an incredible cast of Keanu Reeves, Robert Downey Jr., Woody Harrelson, and Winona Ryder. It is faithful to the book, hypnotic in both visuals and plot, and will go down as a hidden gem.

Sunshine

Sunshine

A common trend in these movies seems to be a great cast. Well, there might not be any entry with a better one than 2007's Sunshine. It is loaded with Chris Evans, Rose Byrne, Cillian Murphy, Benedict Wong, Michelle Yeoh, and that's just to name a few.

It was also helmed by Oscar-winning director Danny Boyle. Sunshine follows a group of astronauts in 2057 who set out to reignite the sun before it dies out and leaves the world in darkness. Part sci-fi thriller, part slasher film, Sunshine is a testament to the talented folks who helped make it happen.

Moon

Sometimes, the best sci-fi movies are the ones that don't go too far in terms of scale. They keep things small and grounded despite their subject matter. That was the case with 2009's Moon, which is about an astronaut struggling at the end of a lonely three-year mining trip on the moon.

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Though it only had a budget of $5 million, Moon looks a lot better than most other films in the genre. That aspect, combined with a tremendous story and a riveting performance from Sam Rockwell, makes this one of the most underrated movies of all-time. Regardless of genre or decade, Moon is a classic.