If you liked the Guilty Crown anime, the Anime-Planet community thinks you'd like:
Simon lives a boring life in the underground village of Jeeha, where his main job day in and day out is to dig tunnels. His close friend Kamina, however, longs to bust out of their oppressive existence and reach the surface world where open skies and adventure await! One day, during his usual digs, Simon discovers a robot with a big face buried amongst the rocks. No sooner has he shown Kamina his mysterious find when two beings from the surface crash land into Jeeha Village - one is a gun-toting woman calling herself Yoko and the other is a terrifying mecha piloted by a Beastman! Seeing their chance to escape village drudgery, Kamina rallies Simon and Yoko to defeat the invader using their new robot, Lagann. However, upon breaking out onto the surface world, Simon, Kamina, and Yoko encounter enemies more powerful than they could have envisioned. Their fight for adventure just turned into a war for the survival of the human race - will their lust for freedom hold out against such terrible odds?
Wimp is the word I would use to describe the main characters of these animes. In both animes you will find that the main characters are both wimps, however through trail and tribulation they end up going farther then they ever thought possible.
Besides the wimpy main characters you will also see the one they hope to be. These characters are the leaders in there respective groups and is loved by everyone. These characters also both challenge the power that supresses the people, drawing in the main characters to help.
So we got, wimpy main characters, Strong and inspiring leaders, are we missing something? Oh yeah how about mecha battles. Both animes have mecha battles however I would say Gurren Lagann has better mecha battles that Guilt Crown.
So to end this I will say this. Both are great, Both will leave you wanting more after each episode but a fair warning Guilty Crown is a bit darker then Gurren Lagann, however I would still recommend watching both because they are both worth your time.