 If you liked
Top wo Nerae! Gunbuster
|
 ...then you might like
Heroic Age
|
Both involve human's battle for survival vs. space monsters. (although the humans in HA don't battle exclusively with space monsters) In both series, the key to victory lies in the hands of a super being/robot. Both feature battles on an epic scale. however, Heroic Age is a more action driven anime, where Top wo Nerae is more of a character driven drama.