First one is old as hell and finding all the secrets - needed for the true ending ofc - is impossible without a guide. It's literally stuff like kill these enemies in this specific order, then walk into these spots in this specific order, everything done in under 3 minutes, and a chest spawns somewhere without any notification.

However, the true ending is how the Nier series started, so it may be worth checking out.

The second game is a continuation of one of the non-true endings. Personally I've only played an hour or two of this game. It's just a copy of the first game, along with all its, umm... charm, but without connection to Nier.

Drakegnard 3 is definitely the best Drakengard game on its own. It's pretty good overall. It's part of the Nier universe and has some interesting tid bits for people who have already played Replicant and/or Automata.

This is the first time I've seen this game mentioned in relation to transfems or lesbians, but I can see why. Basically, to not spoil anything significant, the main character sleeps with defeated bosses' servants. It's supposed to be a way of establishing the power dynamic or something like that.

In short, she's a horny girlboss.