This was the first of several Love Live! TV series and the inspiration for massively popular world idol tours, movies, music albums, and idol related figurines, posters, and products. Promoters and merchandisers have made loads of money from the idols, but that does not change the fact that they are very entertaining. I suspect this show had some inspiration from the series K-On!
Each of the Love Live series is good enough that any one could become your favorite. This original one is my favorite because of the characters and their stories. (However, there are more musical performances in Love Live! Sunshine!) On YouTube you can find several good English covers of the Japanese songs and great samples of the Love Live! World Tours.
The story shows that hard work and determination are necessary, yet do not guarantee success! There are many others out there competing against you, so all you can do is try and find pride in doing your best. Working together and building friendships are a guaranteed reward, but if you can win, then that will be a bonus.
While the show has cute girls in short skirts, it is not focused on boobs and butts or sexual innuendo like many anime. Kids and adults can both enjoy the energy, enthusiasm, dancing and music.