Save mostly on balance spells: Wrath, Starfire, higher ranks of Moonfire and roots (first one is good for pulling and ccing, respectively). Mana-heavy healing like Regrowth, group/raid only spells like Tranquility and rarely used spells like Tiger's Wrath, Soothe Animal, Cower and ranks of Hibernate (again, first one is fine enough for cc) are also a good option. If you don't intend to AoE grind with a group, Hurricane can also be out. This is all PvE-wise. On the other side you may consider getting all Moonfire and Regrowth ranks though due to their usefulness in PvP. For PvE, as stated before, it is nowhere as important to get their higher ranks. It is mostly personal preference.