What genre? It's hard to size some movies up against each other because genres like Drama, Comedy, etc. all go in a different direction with different goals.
It's kinda like deciding who's the better fighter: Stage Combatants or Screen Combatants. I've heard a lot of stage actors say that screen actors don't count as fighters, then they shun me when I tell them how the goals are not the same for Stage directors and Screen directors, resulting in the fact that they can't really be compared against one another.
For Drama:
I say "A Time to Kill" with Katherine Heigl, Samuel L. Jackson, Sandra Bullock and Matthew McConaughey. That was a movie that broke your heart, moved your soul, and resolved in a way that made you feel better than when you began watching it. It's eye-opening, a good watch and I cried a few times. Adapted from John Grisham's book.
Historical:
"Glory" (1989) with Matthew Broderick, Denzel Washington, Morgan Freeman, and Cary Elwes. Based on the letters of Colonel Shaw, this movie was about the 54th Massachusetts, the first All-Black volunteer infantry regiment of the Civil War.
Action:
"Chocolate" with Jeeja Vismistanada. Zen, a mentally handicapped girl, learns how to fight via visual muscle memory. If she sees it, she can do it. It's thai, so the fighting is real (though choreographed) and the pain is real. On several occasions people wound up in the hospital or had to get stitches before they continued with the movie. Tony Jaa is also amazing, but there's something about a normal-looking, everyday petite girl that kicks grown men's asses that puts her above him in my book.
Comedy:
"Rush Hour" with Chris Tucker and Jackie Chan. It's really kind of a comedy-action, but I think it's all hilarious. I could watch Rush Hour 1 and 2 every day and not grow tired of it.