Clear Skies all the time. Weather control has 'blessed by Kyne' written all over it.

In combat usually Whirlwind Sprint 'cos I keep thinking I've got Fus equipped in dungeons after shouting though traps. Ah well, it's a dodge move I suppose.

I think Dragon Aspect was a pretty cool shout, but I still have barely used it.

I try to use shouts. However most of the time I end up using a weapon/magic. I do use the whirlwind sprint quite a bit especially when I'm over encumbered trying to get back to the start of the dungeon or town to sell/store my extra items.

I use aura whisper but that's about it sadly to me most of the shouts are just plain useless. Sure they are cool but I would rather focus on the core mechanics of combat.

I hope shouts do not make a return in future games.

Some spells have some limited utility. Whirlwind Sprint for escaping or avoiding traps.

Become Ethereal for jumping off mountains.

Clear skies is great if you use Frostfall.

Elemental fury and Slowtime are cool and good mechanics.

Unrelenting force for fighting on cliffs.

I think the rest are sort of useless because in the time it takes to use them you could have simply killed your enemy in most cases. And in the times it would be really helpful, like disarm, it won't work on the enemies you need it to work on.

That being said I almost never remember to use shouts even in the situations I mentioned above

I will use the ones I feel are combat based abilities. Disarm, Slow Time, Elemental Fury. But I've never made it through the MQ. I have tons of shouts found and tons of souls unused.

I mostly use the defensive shouts because the offensive ones tend to be lacking in firepower. I use the ethereal shout a lot to avoid damage. Whirlwind sprint is used to get close to mages and archers. Elemental fury is the most offensive one that I use a lot and that's just so my character can flail away on someone.

Fire Breath is best shout for fighting undead in a narrow hallway, that and I just like burning things. :3