For us (last week), EPCOT was the best park during the day. Almost no waits for rides but the world showcase got pretty crowded by evening. I wanted to go on the frozen ride, which had little wait all day. But by the time we got there in the evening, it was too long to bother. Those construction walls, though, yikes.
Magic Kingdom was by far the worst. It was Saturday (and not MLK weekend) so I'm guessing that played into it, but I kept wondering if there was a holiday that I was missing because I couldn't believe the number of people. We got there around noon and waits in the afternoon seemed to be around 50 mins for most things. Should have gotten there early, but I had a teen who didn't want to get up early on his birthday.

Some areas were super crowded. And rides with long waits that had queues into main walking areas without ropes (I'm looking at you, Haunted Mansion) were a free for all. It was so crowded that people were just hopping into lines at random places, not realizing where the line started. I joked to DS that you know it's bad when the teacups and Mickey's Philharmagic had a wait.

It emptied around 7pm (for 9pm closing) and was great then.
DHS wasn't too bad. Though for the first time we did not get a boarding pass for Rise of the Resistance at 7am. Had no problem getting one thanksgiving week. Luckily did get one at 1pm. We skipped AK.
ETA: We went on Smugglers Run (I think that's the name, not a star wars fan but DS is) and ended up put with another group of 2, they got the pilot seats so we were in the back. Engineers, I think, but really you do absolutely nothing. So DS wanted another try and we went again. Luckily we were by ourselves that time and able to be pilots. I've got to say, I've been on it several times and never been a pilot (because I have 2 teen boys who always jump in those seats). That ride is way more fun when you're a pilot, I'm going to start fighting them for it from now on. Also, we had a wait in a virtual queue to be able to look at the "legacy lightsabers," that's never happened before. It was quick though.