Over on TikTok, Jaysea Lynn, aka Sea.ya.Later created a sketch series. 
Based on the concepts of Hell, reincarnation, and universal constants the series revolves around Lily, the creator of the Hellp Desk in Hell, helping to direct souls to their punishments or paradises. Throughout the sketches many books are seen being read by the many denizens of the Afterlife. They are often romance novels of a spicy nature, or informational non-fiction. 

This is an INCOMPLETE list, as three videos have unidentified books (and neither I, nor the comments section, could figure them out) as well as the fact that the series itself is ongoing. 
I will update as new books are added, and if anyone can identify the books from videos 145, 286, and 466. Some videos are out of order, or books were reused multiple times. Some books are parts of series, and are not necessarily book one. I do recommend reading series in order, but that is up to you, as the reader.

As TikTok has an uncertain future, Jaysea is uploading the compilations on YouTube, and I wholeheartedly recommend watching them. I will put no time limit on this challenge as the series is ongoing.

***I am not Jaysea Lynn, nor am I affiliated with her in any way. The Hell's Belles belong to her. Please go watch and support her by reading her book! I promise it is worth it.