Oh, I love having music in the shower! I’m using a JBL Clip 4 right now and it’s super good. It’s waterproof, has easy buttons for skipping songs and the sound is really clear for its size. I just hang it on the shower rack and it never slips or gets weird with the steam. I’ve also heard the Anker Soundcore Mini 3 is great too and a bit cheaper. Both hold a charge for a long time which is nice when you forget to plug it in for days like I do sometimes.
If you want something that looks a bit fancier, the Ultimate Ears WONDERBOOM 3 is another good one. It’s completely waterproof and even floats, so you can use it by the pool too. I think it really depends on your budget but any of those would make shower time a lot more fun.