Since other anons are talking about non-Disgaea NIS games...

I played Rhapsody (PS1) recently. The beginning is full of quality, effort, etc... but good lord, the ending was rushed and the midgame is all filler. Nothing but a dozen copy-paste dungeons using the same 2 tilesets tinted in slightly different colors. Not to mention key items that do nothing and no rewards for completing the puppet quests. They clearly ran out of budget.

If only it could have maintained this level of quality throughout the entire game: https://files.catbox.moe/euvla4.webm