if this is just about Disgaea I'd have to say number 2, but if you count other NIS titles it is DEFINITELY Phantom Brave, I loved that game, you could be like... level 20 and slaughter lever 200's it was AWESOME
Definitely Disgaea 2; hands down. The second one made team attacks easier and you didn't lose your turn while having multiple people attack the same enemy if it was killed quicker than expected. (I hope Disgaea 3 can outdo some of the issues with movement that the other two had and provide some uniqueness for the series to spruce it up a bit).