I gotta recommend 12 Angry Men. It does come from a play so it can be a bit theatrical with people talking about the American trial and jury system and some of the character's behavior motivation. Yet, the story and material are strong and it keeps moving along that these moments don't linger too long and, as a viewer, it doesn't quite break the suspension of disbelief. Which is good because it definitely has moments that wouldn't normally be allowed from jury members.
If you like Ace Attorney then you'd probably like this film. It's basically the jury conducting the trial themselves as they go through evidence to look for the truth. A lot of this stuff should have been done in the trial by lawyers but it is explained away in a believable enough manner. TCM just had it on a couple weekends ago. I came in the middle just to see where it was at before shutting off the TV only to stay engrossed until the end again.
The first time I saw it was around 2002. I think I had rented it from Blockbuster. My brother is not a fan of older movies. He complains about the acting styles in the 30-60s nor does he care for black-and-white movies. I'd recommend Hitchcock movies or other classics with Bogart or Jimmy Stewart but he's pass on seeing them. I told him the plot of this one and how it was a top-rated classic. The plot interested him enough to see it with me and after he said he did like it also. So, it doesn't surprise me that it is rated so high on the IMDB list. Personally, there are a lot of other classic movies I'd rank ahead of it but it is definitely a crowdpleaser and it is a movie that I think most people will enjoy so it has broad appeal even if it may not be the most stunning film technically.