Does anyone know who are all the essential NPC's? I know Mjoll is that's about it.

Here you go.

http://www.uesp.net/wiki/Skyrim:Essential_NPCs

I think it's easier to make a list of non-essential (named) NPCs.

It's funny cause it's true.

Who would be the best? I've used Mjoll and I'm tired of the same ol thing.

unfortunately, majority of the NPCS that we want dead(e.g. maven, silverbloods, those milkdrinkers) are essential. Bethesda why are you torturing us ><

I knew there were a lot of essential NPCs, but that list is much longer than I thought it would be. Boo!

So you want a list of followers, not essential NPCs?
You can find this list on the same website linked to you from the initial question.

I didn't really think that they were over-using the essential flag until I tried to kill Rolff Stone-Fist, the racist guy who runs around the Gray Quarter in Windhelm being a bag of awful, and found out he was essential. Same with Gisli, or you can just call her Erikur's sister, in Solitude. I'm assuming it's because their family is important, what with Rolff being brother to Ulfric's second-in-command and Gisli being the sister of a Thane and potential Thieves Guild backer but still...they add nothing to the game, I should be able to run them through. >:

Derkeethus, Cicero, Mijoll, and the two Dark Brotherhood initiates are the only essential followers to my knowledge.