I think my favorite non-cylendar design would be the Imperial-Class Star Destroyer.

The wedge shape means that every single weapon on its superstructure, except directly aft, can be aimed forward.

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And you, to whom adversity has dealt the final blow
With smiling [faces] lyin' to ye' everywhere ye' go
Turn to, and put out all your strength of arm and heart and brain
And like the Mary Ellen Carter, rise again.