Crafty Carts (remake) is a pretty snazzy one. Great for building a fancy base somewhere or on the move repairing of things.

(Jotunn)Backpacks. A potentially OP storage option that balances out quite well. Good for pack-rat hoarders or 'Lost' explorers.

PlanBuild is great for those visual builders who need to see what they're working with, or just want to plan something epic but don't have the materials right now...

I am also an advocate of various portal mods that stop the (arbitrary) limit to taking non-used metal through a portal (If you're going to stop us portalling ingots, why can we take the sword that takes so many of them to make?)

Passive Forsaken Powers is a little OP mod that makes all those abilities permanent, but I had to get that and manually install it from Nexus, rather than the Thunder Store Manager