I use a large of variety of shouts depending on my opponents, their numbers and my surroundings. Fire breath (All Three Words) is great for clearing corridors. Unrelenting Force (ATW) can be used similairly or to push opponents into hazards. Ice Form (Two Words) is typically used to CC a boss while I deal with his adds. Aura whisper (One word) for when im sneaking and I want to know where my enemies are. Whirlwind Sprint (TW) I use for quick getaways. Become Ethereal (ATW) i use to jump off mountains or survive a dragons breath attack. Disarm (TW) for creating an opening on opponents with shields. Throw Voice (ATW) for distracting whilst sneaking.
And these are just the shouts I use, I have many more (unlocked) that I don't, like: Frost Breath, Elemental fury and clear skies.
The way I see it my shouts give me a distinct advantage over the majority of enemies in skyrim and I am gonna use every advantage I can get (I'm not an OP Mage so the game is actually challenging)