"Good" or "Bad" is
very subjective. My gf adores Botania for example whereas I'm more into Mekanism. And of course.. this whole thing also depends on what kind of direction you want to take things. You have tech mods which add machinery and metal ores to the game, there can also be magic involved and of course other mechanics.
Maybe look into modpacks to get started? Modpacks are collection of mods set up by others and they should provide a specific game experience.
But yah, it
really depends on what you like to play with.
My suggestion is to hop over to CurseForge, select a category and then sort on popularity. No guarantees but it certainly gives you a good impression. Just make sure you
always look into the "relations" tab and satisfy any required dependencies: many mods rely on others, such as library mods. And pay good attention, because some popular mods sometimes turn out to be crappy anyway (=
strictly personal opinion) because they don't bother to list any requirements but simply write those out in their main description page, making it a lot harder for us users who don't want to bother with "intrusive" loaders. Each to their own but I ignore such mods out of principle alone.
Anywhoo.... I do have some suggestions to look into and even without any bias involved! ;)
- Just Enough Items (JEI) => If you're playing 'modded' then this is a must have. This has nothing to do with personal bias btw: before we had the Minecraft recipe book we already had JEI which quickly became the defacto standard for learning about recipes. Pretty much every mod in existence knows and supports JEI, if not plain out relies on it for allowing you to dive into their recipe structure(s). It can also detect items in your inventory so if you have the required items while having a crafting table open then all you have to do is click '+' and your recipe will be set up for you. The reason why this is a big deal is because 'modded' also has a lot of so called "deep crafting" as I call it: the need to craft other items in your current recipe.
- Map mods => Playing modded also somewhat implies doing a lot of different things in a lot of different places. So it may help to keep track of everything, which is where a "map mod" can help. It usually gives you a minimap so you can keep track of your direct surroundings, and a bigger map to give you a better overview. Some awesome features include waypoints (= markers to remind you of certain places), deathpoints (= automatic marker to the location where you last died), entity radar (= showing you mobs in your area) and other optional settings. Some even allow you to share waypoints in chat, which can be a really cool feature.
- Storage mods => Playing modded is pretty much a guarantee for a severe increase in the existing blocks for the game. For example... my JEI overview has 16 pages in its overlay which list vanilla Minecraft items. ... out of a total of 73 (!) pages, meaning that my mods added 73 - 16 = 57 pages worth of new items, so roughly 3 times more items than you got in the vanilla game. Sure, not all of them are obtainable, but it does beg the question: where are you going to store all that new stuff? Fun fact: my friend and me even play with a rather small collection of mods ;)
- Tech mods => Ever fancied to automate more things in Minecraft than redstone alone can do for you? Then this may be fun: build machines like automated smelters, maybe do even more with your items with crushers, infuse items and sometimes maybe even evaporate stuff. These kind of mods also often add more metals into the world like tin, lead, silver, nickel and sometimes also alloys like bronze (and the mechanics to make such alloys!).
- Magic mods => Dive into the arcane and do "magical" stuff. This usually implies tapping into resources which can gain you specific abilities, either on your own of by using specific tools. Bear in mind that the border between tech and magic is often blurred.
And of course there's plenty more. Just focus on what might interest you. Like working with redstone? There are mods to expand on its capabilities. Enjoy exploring? Maybe you'd like to add dozens of new biomes with ditto new animals? Fun fact: a lot of the recent animals in Minecraft already somewhat existing within several mods. Heck, even copper already existed
long before Mojang decided to add it.
So yah, hope that this can give you some ideas.
Like I said: maybe use some modpacks or ... just grab some mods of your own to see if you enjoy playing with them.
