Is it possible to do so without joining imperials? I'm on the quest where i have to return the jagged crown but it looks better on my head then ulfric so i want to keep it. I also want to do the main quest but i can't keep the crown so i'm stuck.
Did anyone figure out a way to keep the crown and do the MQ? I'm playing xbox btw so no console commands

The main Quest isn't the battle between the Stormcloaks and the Imperials- it's the fufillment of the Dragon Prophecy.

You can always keep the crown, but you can't complete the quest if you don't deliver it to either Ulfric OR the Imperials.

The only way you could progress through the "War questline" while keeping the jagged crown is via console commands.

I don't think you have to do any of the Civil War quests to do the main quest. You should just be able to keep it. That being said I'm not sure.

You can't 'quit' the stormcloaks, but you can take the crown to Tullius if you want to switch sides, and to Ulfric if you're with the imperials.

Picking a side before finishing the MQ requires you to finish the war 1st.

I wonder if i did the MQ 1st could i still join the stormcloaks after and get the crown?

Stop going to the meetings and you will probably be fired

Actually, Ulfric starts sending a courier to your house everyday with "Hi, uh, Dovahkiin? Just wondering where you are. It's Ulfric again, yeah, I just wanted to make sure that you knew, uh we did start at the usual time this morning... oh and I'm gonna need you to go ahead and come in on Loredas, okay? Thanks, buh bye."

Eventually, because of your attitude of personal initiative, you get promoted into Stormcloak upper management.

Of course everything I just said was a LIE! Including this. And this. And this...

There could be a bug in part of the main quest later if you have not finished the civil war quest (Read http://www.uesp.net/wiki/Skyrim:Season_Unending to see what the bugs will be)

I think it would be better to complete the Civil War Quest before you get too far with the main quest (that is what I have done, I will do it differently with the next character)

You don't have to pick a side at all to complete the Main Quest- you don't *have* to join with the Stormcloaks OR imperial in order to progress with the Main Quest (though by doing so you run the risk of a bug late in the Main Quest- something goes wrong with the temporary truce part and it never gets finished.)

THe answer to your question is yes, though. Once you complete the Main Quest, the game does not end, and you can still do everything you want in terms of joining up with either side in the war.