Tenkuu no Escaflowne, Heroic Age Recommendations
Both are adventure stories, with an equal share of action and romance aswell. They also both weave elements of ancient mythology into their settings and stories. The main female characters are also similar, both possesing mental powers above others. Mecha are both portrayed in a more original way, than what you would normally see.
both have mecca but if your looking for a little more drama and romance with action and a lotta fighting then escaflowne is a must see. The art in esca is wonderful even though it is a bit old. watch it...it will not dissapoint!
Both are Sci-fi anime with a female lead and a power male who fights for her, using am unorthodox mecha.