Terraria's Calamity mod is probably one of the best content mods that Terraria has. The only people who hate it just want to be different badly. That mod is actually good and unique. There's a good reason why it's so popular, it's genuinely so good.
Lots of lore for lorecucks, lots of bosses for like 99% of people who play Terraria to do a bush rush with a class locked challenge, visually good weapons, great textures, entertaining bosses, interesting vanilla changes that spice up vanilla weapons, True melee expansion and way more. It is not a bad mod in any way and unlike other Terraria mods, it is actually complete enough to do a full playthrough on it. My only issue is that they haven't added more summoner whips yet, and completely misunderstand whips. Shyguymask was right about the Calamity mod.
Fargo's soul is also good. Like, it is pretty much a total expansion on vanilla Terraria since the mod completely revolves around vanilla rather than adding new stuff. Like, the idea of grinding vanilla content to make fusions of vanilla accessories that give you all the powers of vanilla biomes and object classes is so good. The boss changes, while extremely difficult, offer an interesting change of pace. My only issue is that they haven't added more whips or more accessories that interact with whips. I need armor and accessories that make me start whipmaxxing.
I could badmouth certain mods too, though. There are some I would absolutely badmouth, but they're small and unpopular, so I'd feel like bullying a little kid if I do that.
Oh, and Homeward journey sucks ass, it only got big because it was the first content mod in 1.4.4. Other than that, it's bad.
Also, Stars above sucks. The bosses are bad and boring. It is waifubait garbage with little substance. It feels like a collection of random weapons rather than a content mod, rather than a mod with a clearcut aim. If you remove all the references to other games and series, you remove 90% of the content in the mod. It can't stand on its own. It's also very unbalanced. Why does every weapon need to be so complex just for those weapons to be bad? The weapons seem more like gimmicks than actually good weapons.
Also, Split mod, Spirit mod, TRAE and Thorium are peak.