A beautifully drawn and rendered anime OVA series from the 1980s is Dangaio.
With mecha designs by Shoji Kawamori, this giant robot action series is the cream of the crop of that genre.
Dangaio is well worth the money if you can find the DVDs.
It was originally put out on VHS by the now defunct US Renditions.
Currently Manga ENT is the distributor.