Probably the most realistic sci-fi anime ever.

It's a beautiful thing when art and science collide.

I bet you think this post is about you, don't you, don't you, don't you, DON'T YOU!?

Yeah, if Apollo 13 is a 10, Planetes has got to be a 9.

It's been a while, but I think Mighty Space Miners might have been a contender as well...but god damn was the dialogue cheesy.

Wings of Honneamise maintains its realism by shying away from having to be detailed.

Ghost in the Shell SAC is pretty good, but has a completely different focus, and gets a little hollywood with its representations of OMG THE NET. Is there anything else that is even in contention?