Fallout

I use Start Me Up, which is fun if you want to roleplay. It lets you choose where to start, and it works in the main quest with tweaked dialogue.

Most of the rest of mine have to do with settlements and crafting. Armorsmith Extended and Universal Clothing Overhaul are my favorites. Place Anywhere does exactly what it sounds like, and best of all it lets you move things up and down and toggle the snapping features on and off.