Legend of Galactic heroes is the definite space opera anime.
It is an intellectual anime, not because of some convoluted plot or esoteric topic, but because of the sense of scale and the amount of detail packed into it. It always assumes you understand what's going on and doesn't hold your hand.
Start out with the prequel movie My Conquest is the Sea of Stars and then Overture to a New War (which is a cinematic retelling of the first two episodes) to see if it catches your interest. If it does then you can either skip the first two episodes or watch them for the sake of completion. Be warned that the first season has a couple of problems with pacing and animation. But stick through it and you will be rewarded with one of the greatest anime productions of all time.
It is an intellectual anime, not because of some convoluted plot or esoteric topic, but because of the sense of scale and the amount of detail packed into it. It always assumes you understand what's going on and doesn't hold your hand.
Start out with the prequel movie My Conquest is the Sea of Stars and then Overture to a New War (which is a cinematic retelling of the first two episodes) to see if it catches your interest. If it does then you can either skip the first two episodes or watch them for the sake of completion. Be warned that the first season has a couple of problems with pacing and animation. But stick through it and you will be rewarded with one of the greatest anime productions of all time.