C, D, E and G are my Favorites but considering its going to be background music I like G so far the most since its the most fitting as well as because its quite relaxing and chill, which i really love. H really is quite epic to listen to as well which surely wouldnt make bad bgm. I really reminds me of some sort of great journey through space and time like the current bgm but theres something which I dont enjoy about it...
J sounds quite cool but since its not my style I wont vote for it <.<