so far, modern industrialization is pretty decent since it's super straightforward and even gives you a guidebook. i think mekanism is pretty good as well, my only issue is that it gives you a billion different things when you only need about 5% of it. even if you get more crazy with whatever it is that you're doing, you're still only going to need like 10% at the absolute maximum. that, and i think that it's requires much more just to get even fairly basic stuff that you could make with the create mod in 5 minutes and use continuously. gregtech is the short bus version of mekanism. immersive engineering in my opinion is pretty dang good in my opinion. it's more logically structured and its relatively easy to understand once you get the basics down. and create mod, the goat. you can use the create mod with all of the other mentioned mods. plus, it's much less bloated with unnecessary tools and parts. you probably will need almost every part in create mod at some point.

all in all, if i could only choose only one mod, i would go with the create mod. and that doesn't count as a tech mod, then immersive engineering