I'm not a super-experienced healer, but this 63 Resto Shaman seems pretty engaging. I use Healing Wave a lot, but the way the class is designed I couldn't get by with using it exclusively.
My bread-and-butter is Earth Shield. It's not a very interactive spell, but it's what I actually rely on to keep the tank stable while I wait on slow casts. Additionally it works well with the Shaman play-style since it buys me a little time to change my totems, or change my positioning if I need to.
Healing Wave alone is a little too slow to rely on, so I often use Chain Heal first, when the tank hasn't really taken much damage. It decreases the cast time of Healing Wave by 30% and increases the crit chance of Healing Surge by the same, so Chain Heal seems to be a good preparation for casting a more clutch spell.
Healing Surge is for when everything goes pear-shaped. I might use it on the tank at the very beginning of a pull (when he gets clobbered before all his defenses are active) or the very end of the pull (when he has debuffs or DOTs stacked up). Mostly Healing Surge is used for keeping DPSers or myself alive though. I can't really afford to stand there and spam long heals on anyone but the tank, so if I need to shift my focus I try to take care of things with one big heal.
I can't use Nature's Swiftness on every pull, but I use it quite often, usually paired with Healing Surge. Since I need to use Chain Heal as part of my rotation to keep my peak healing, I'll occasionally need to drop a big heal instantly afterwards.
I'm counting 4 heals that I use regularly, and have to adapt to the particular situation. On top of those I need to track not only my mana, but the DPSers' so I can throw down my mana tide totem at the right time, I need to drop my tremor totem for certain fights (using long-cast heals while running to put a totem in a particular place is kind of tough), and I need to stay alert to purge enemies and cleanse friends. I'm definitely not just standing there casting Healing Wave.
At lower levels when I had fewer abilities available, I just didn't spend all my time healing. Probably about a third of my spells were shocks or lighting bolts. Most tanks can survive most pulls with Earth Shield alone if they really need to, so there's a little time to use other spells. Even at 60+ I could throw in shocks on nearly every cooldown if I wanted, and I probably could slip a few Lighting Bolts in if I didn't mind letting the tank's health bounce around a little.
It seems like the OP is complaining about Paladins, so maybe it's just Paladins that are dull? A lot of the flexibility I see with my Shaman comes from Earth Shield, which frequently allows me to ignore healing, shift my focus, or use less efficient abilities to set up procs for more efficient ones. Now that I have the Earthliving weapon buff the effect is even more pronounced; since Chain Heal is a part of my regular rotation I end up having HOTs on most of the party most of the time, so if I want to get creative I probably have the time to do so. I could see where a class without any HOTs would be more locked into spamming heals, since there would be no way to stabilize the tank if you wanted to stop the spam.
At any rate I'm definitely not just standing there spamming one heal, and I never have with this character.