I would recommend avoiding the memes pack. One of the biggest criticisms of RBN was that it was all metal and internet meme songs; the latter in particular made a ton of people not take it seriously. As much as I like “Yatta!”, I think that authoring time is better spent on the other packs you mention.
You are about to leave Rhythm Gaming World and access the external songs DB. While no song or file sold for commercially available videogames is hosted there and only fan generated content is allowed, Rhythm Gaming World has no direct control over the database and no files are hosted here. Alright, we had to made you aware of this, now you can visit the database!