Wreck-It Ralph (2012) - The perfect version of the hero's journey. He even wants a badge with 'Hero' on it at the beginning.
Inside Out (2015) - A wonderful investigation of our inner lives.
Big Hero 6 (2014) - Cool kids prevail. Cool = nerds.
Mad Max: Fury Road (2015) - Uh, yeah. I mean... Uh, yeah.
Guardians of the Galaxy (2014) - Popped the 'we must be serious' approach to COMIC book stories.
The only one on your list I haven't seen is
Wreck-It Ralph. I had both
Inside Out and
Big Hero 6 in my honorable mentions. Cool to see some overlap on
Mad Max and
Guardians, and my reasoning for including them is pretty much the same.
5. Edge of Tomorrow (2014)
4. The Lego Movie (2014)
3. Les Miserables (2012)
2. The Avengers (2012)
1. The Martian (2015)
For me, the best movie of the decade is The Martian, and it's not even close. It's an absolute triumph of the human spirit.
Disclaimer: There are some very popular movies from this decade that I haven't seen but might like a lot. The King's Speech (2010), for example. Since I haven't seen it, though, I can't intelligently include it in the conversation.
Disclaimer 2: For the purpose of this thread, I'm including 2010 in this decade even though it's technically part of the previous decade.
Oh, man, I had a hard time keeping
Edge of Tomorrow and
The Lego Movie out of my top 5. Love those flicks. Haven't seen
Les Mis, and I liked
The Avengers and
The Martian.
And, yes, I was including 2010 as well (had a hard time cutting
Inception from my list). 2010-2019. I don't know if that's technically incorrect, but that's what I was counting as being "the decade" in question.