Tactics Ogre Reborn should definitely be on this list. Its level cap system forces you to really think about your moves on the grid and preparation becomes vital.
Once I learned that Triangle Strategy let's you keep the EXP gained from a battle you lost, it soured the challenge of it all cause I knew that I could just throw myself at enemies and focus more on levelling up than beating the mission - especially cause there's no perma-death.
