what did Gandalf look like
 

What did Gandalf look like before he was sent to middle earth...And what whas the name of the other wizards that also came to middle earth with him..

Gandalf is a Maia and does not have any true physical form. In Valinor, the Ainur's physical appearances were generally a function of their mood or disposition. Gandalf, like the other Ainur, could walk uncloaked if he wished, in which case he would be invisible to all races and creatures but other Ainur.

the other wizards that were sent with him were, Sauruman, Radagast, Pallando, and Allatar

gandalf looked like a spirit no shape and no form

When they walked uncloaked, the Ainur were like living flames, too bright for any non-"divine" eye to look upon for long. Most often, they were clad in bodies, but those bodies were like unto raiment for mortals. They were able to cast it off at will, with no harm to their spirit.

Has anyone here seen the dark crystal? If so then i always pictured them as the guys at the end who all you see is crowns and a blinding white light. Then when they go to earth they assume the forms of humans.

The form Gandalf took when he had to was apparently the same as the Gandalf the Grey we all know, since it was so when he appeared at the Council of the Valar.
See also our FAQ or questions on the other wizards.