What had left its impression on me thus far is the opening theme to Gundam 00. The opening montage uses popular Japanese band L'Arc-en-Ciel's 33rd single Daybreak Bell. The song is one of those that grows on you, in my opinion. It starts somewhat slow then builds up to provide that burst of energy in the chorus. It works well listening to it side by side with my current other song-to-listen, Rule the World by Take That. In fact, if one were to read the lyrics of both songs (give & take a bit for Daybreak Bell's translation), both tell a hope-like story, sensitive, with a happy climax.
I managed to upload the 1st opening montage of Gundam 00 for mOAm readers interested in checking out a brief version of Daybreak's Bell as well as the animation of Gundam 00. For Rule the World, it's a Youtube video where you can checkout the song plus some scenes from the movie Stardust, which in my opinion is worth going to the cinema to watch since I didn't say it in my review of the movie (in fact, I don't mind watching it a 2nd time). Enjoy.
Till later, live long & prosper.