Can you take followers to the island and if so which one is the best?

You can take any follower there, and the best is up to you. There are some new followers on Solstheim too though~

I took Serana there. I enjoyed the experience. But someone else might not. There is no such thing as a "best" follower. We are all different people with different tastes, and that means the followers we like are going to be different also.

I roleplay, so I tend to pick followers that make sense to be traveling with the character I'm playing. But even from a strictly game play perspective, I think it depends highly on what type of character you are playing. I like to recruit ranged (mage or bow-wielding) followers if I am playing a melee character and recruit melee followers if I am playing a ranged character.

I was thinking in terms of what was needed there.