I've had my CubeCart store up and running for a few months now & want to add some Mod's.
What are the essential mods you can't live without?

This would be better discussed over at cubecartforums.org, where the mod authors are free to promote their wares. Forum advertising rules here prohibit such promotion. If you wish to continue this topic here, please take this into account.

Also, CubeCart 4.x features more built-in functions than it's 3.x predecessor, so in some cases, there is no need for additional modifications.