Story wise, when you begin watching the series you initially think that it's not supposed to be taken seriously. However, after a few episodes the sheer "epicness" of the plot and characters pulls you in and it becomes the ultimate story which must be handled as a serious matter. It's also something that borrows, or rather parodies other mech and apocalyptic series. Even so, it incorporates these elements in a way that only contributes to its originality. It's everything you've come to expect from Gainax (FLCL, Eva, Abenobashi).
The characters really are the soul of the show. It could be said Gurren Lagann is plot driven but it would also have to be said that the plot is character driven. I swear that you will fall in love with Simon, Yoko, Kitan, Viral, and yes, even sweet sweet Kamina.
The music of Gurren Lagann is another key draw. Songs like "Sky-Blue Days" and "'Libera me' from hell" do more to contribute to the enjoyment of this series than the characters or plot do for many other shows that have been released recently.
Animation wise....IT'S GAINAX!!! Their name has become synonymous with beautiful animation.
Overall, Tengen Toppa Gurren Lagann is series that will reaffirm our faith in Japanese animators. It shows that not everything of late is formulaic crap. Thank you and FIGHT THE POWER!
