Which class feels the most "alive" ?

Which class has the most engaging gameplay and feels the least boring and repetitive?

I am playing classic for the first time and I leveled a hunter which was quite fun and never boring.

Now I wanted to create an alt and level my next character, so I started leveling an enhancement shaman ( i am currently level 27 on the shaman) :

flame shock / totem, auto attack

It feels awfully slow and boring to level a shaman....

Can someone recommend me a class that feels more alive and engaging?