Judaism: Incredibly boring. The idea of being part of the Jewish community has its appeal, but what little I've read of the Talmud suggests to me that it's a more effective sleep aid than Nyquil. Haven't been able to find the interesting legends and anecdotes that it supposedly contains. Learning Hebrew and then reading the Tanakh in that language sounds like it could be fun but also super hard and I don't imagine that all Jews are able to do it. Being a boring religion isn't all bad, though, because it lends itself to moderation. Jews are among the few non-white races willing to genuinely acknowledge and criticize their own side's bigotry and racism, and I can respect that.
Catholicism: I have had a little real-world exposure to Catholicism in the form of "Radio Maria", a terrible quality radio program that I sometimes play in my car. And yes, listening to it has reaffirmed all the stereotypes I already had about Catholicism (the other day its presenter unironically said you have to be perfect to get into Heaven and framed this as something doable by human effort). Immersion in a culture with a heavy degree of continuity with that of Medieval Europe could be interesting, but in practice it's retarded. A lot of emphasis on repetitious prayer, which I can attest as someone who mentally repeats mantras often of a religious nature to counter intrusive thoughts doesn't do anything to make you a better person. I can't rule out that it does if you're deeply meditating on the meaning of the words, but I imagine that for your average Catholic it's just a mindless chore.
Eastern Orthodoxy: I once thought they were cool, and not from the usual internet "Orthobro" exposure. Rather, back when I was still in college I wrote a paper on the Old Believers and did something of a deep dive into Russian Orthodox spirituality and what I read impressed me. They've got a neat aesthetic going on but I do think in the long term they're going to go the way of the dinosaurs. Their tendency to jump in bed with authoritarian strongmen isn't doing them any favors.
Mormonism: Everyone but Mormons themselves understands this to be a fake religion invented by a known conman, but they're too brainwashed to admit it. I imagine most of them are decent people though, and it's nice to see a group of white Americans with a relatively high birthrate and wholesome family values (though the Amish do it better).
Hinduism: The most archaic of the world religions by far, and it shows. Hinduism still incorporates use of animal dung into rituals and devotional practices, and tries to preserve a late Bronze Age caste system with a vast untouchable class in the 21st century. On paper it and Buddhism are the most intellectually sophisticated religions, but it really seems like they just endlessly heap ideas on top of ideas without it doing anyone any good. India today is pretty much Sub-Saharan Africa with some impressive old buildings thrown in. Reincarnation as a concept was known to many ancient societies, including in Europe.
Buddhism: A strand of Hinduism that went cosmopolitan and adapted itself well to local conditions across East Asia. It has the strengths of Hinduism without its weaknesses. But it doesn't have that much appeal to me.
Islam: The closest to Christianity of all non-Christian religions, since it developed within a Judeo-Christian milieu and incorporates aspects of both. Paradoxically, the non-Christian religion most likely to do violence against Christians. It's also the opposite of Christianity in that, whereas Jesus was a morally ideal man whose followers have very much struggled to live up to that, Islam was founded by an obvious pedo whose followers have worked to be better than him and reinterpret the religion in a sophisticated light, i.e. Sufism. When you take into account fundamentalist strains, it's just barely better suited for the modern world than Hinduism.
Confucianism: A political philosophy disguised as a religion.
Taoism: I know next to nothing about Taoism. Something something yin and yang.
Shinto: I know next to nothing about Shinto aside from the tourist spots I've seen depicted in anime. Pretty much a dead religion nowadays.
Sikhism: An eclectic mix of Islam and Hinduism. They don't strike me as being half as interesting as this description would imply.
Atheism: There's a whole lot of normal people who in practice don't believe in God and just live their lives without involvement in religion, but Atheists are a bunch of terminally online fat guys who make their entire personality out of it.