Papoy
DON'T EXPECT SPOILER WARNINGS FROM ME
I've heard of Sofia, but never tried using her. I've used Miraak - The follower mod. To skip bothersome details, it comes with fun turn in questline after which he is recruitable. He has his own set of shouts, which you can modify. His arsenal is small, but uses them often which easily makes him strongest follower out there, without giving him any unique op abilities or goditems.Sidenote: If you guys have never had Sofia as a companion, definitely try having her tag along on your adventure some time.
I was also wondering if anyone has any fave vanilla or mod companions?
Other than that, I like cheating a bit, and add Raloff/Hadvar as follower through addfac console commands. Sad that game makes them useless after Civil War questline. AS vanilla-vanilla follower, Calder all the way.