My problem with answering this question is that what I view as fun as a healer doesn't seem to jive with the dev teams idea of what a healer is/should be: I enjoy spending most of the GCD on DPSing and weaving oGCD heals between them. I would go as far to classify myself as more of a Green DPS then a Healer and I'm more then fine with that.

An example of when I had fun as a healer would be my run of Paglth'an yesterday; The tank pulled wall-to-wall whenever a gate opened and used their cooldowns competently, while the DPS avoided most telegraphed AoEs while using their party buffs on cooldown and focusing on AoEing large groups. This allowed me to focus more on DPS and cards, use Celestial Intersection's shield on cooldown, and heal by either manually detonating upgraded Earthly Stars or Essential Dignity (with random Celestial Opposition or Aspected Benefic HoTs thrown in and Horoscope for boss AoEs).