The 2 announced (I predict a third one will be announced later) are Crisis on Infinite Earths and Watchmen.
For Crisis I think this might be good. It will be part of the Tomorrowverse, so I really hope they just make a big story that does not reset anything, as it is going well (much better than the DCAMU). I am worried it is going to combine the animated movies with the upcoming live action universe, which I think will be a disaster.
Another key problem is the Arrowverse recently did their own adaptation. It is best to wait until it is no longer fresh in the mind of audiences.
For Watchmen this just sounds awful. It is 600 pages crammed into a movie that will most certainly be 90 minutes long at most. I really think this will be another The Killing Joke. A work that will never work well as a movie, gets highly anticipated anyway, and it then completely falls on its face.
The Animation Historian 