I'm talking in terms of power, not who you actually like. I've hired Marcurio, he seems to fry anything that gets too close to me before I can even get a swing at them.

Reminds of a certain super mutant with a laser gatling gun.

That super mutant you talk about is Fawkes
Or something like that name...
You can just check the Skyrim wiki page for the best idea of all followers you can get.

I like Marcurio too. He's a tough mage. He also has interesting things to say when we enter Dwemer ruins.