Raphael - the Delaware "franchise tax" is the equivalent to the "annual fee" charged in other states, however in Delaware this fee can be in the tens of thousands of dollars. It is a tax in name only, but otherwise looks and feels like an annual fee.
Note also that registering/incorporating/forming in another state other than the one in which you reside will also require the entity to hire a "resident agent" or "registered agent." This typically costs an additional $200 to $400 per year, but you can be the resident/registered agent if you are a resident of the state.
Overall - people waste about $1K when they register an entity in a state other than the one in which the company will actually have its office. They waste even more going through legalzoom or some equivalent.
And no, an LLC is NOT a corporation. It is an un-incorporated entity under every state's law. An LLC could be taxed as a corporation, but that's a whole different discussion.