I enjoyed "For All Mankind", "See", and "The Invasion". I get it for free due to a laptop purchase. I'm not sure if I'll pay for it once that runs out..
Those are all good as well, but I'm sure the person you're replying to was unaware that they could watch them.
The UX of Apple TV+(which is a terrible name) is nothing but bait and switch. After my first week of using my free subscription I completely gave up on trying to browse on the app.
90% of the content I would click on would then ask me for 5 to twenty dollars to pay for it, which is ultimately just a rental until Apple decides they aren't interested in running a streaming service anymore. There's no indication it's pay until you're already excited to watch a show and click on it.
There are good shows on there now, but I only ever bother to open the app when I see an article listing best shows on streaming services and happen to see an Apple one. Sitting down to relax and just opening the app brings about nothing but frustration.
I agree, the app is horrifically bad. Its hard to find the included content, it takes a long time for it to bring up the description of the video, the play delay is terrible, and it has smooth fast forward/rewind which I personally despise.
The only thing that makes it worth dealing with is the excellent content. Oh, and the fact that I can generally download something quickly to watch on a plane after boarding but before takeoff, since T-Mobile throttles Netflix, but apparently not AppleTV.