Someone please help me choose what I make my main!

[Estu]

Well, first of all, don't go Wizard; they're boring and they're nearly useless in groups.

If you love tanking, SK is a good choice. They can also solo somewhat. They're not very useful in raids, though; in raids you almost always have warriors tanking.

Magician and Shaman are both good overall choices. Magicians are better soloers (until your later levels, anyway), shamans are better in groups, but both are very useful in groups and raids. Magicians are rather boring to play; shamans are a lot more interesting.

Necromancer is like magician, but more interesting to play, better at soloing, and less useful in groups and raids.