The following items often end up in my "waste chest" (a chest full of stuff I don't need anymore because of superior upgrades):
- Burner Inserters: Should they be a requirement for normal inserters? Would people use more burner inserters if they could upgrade them?
- Burner Mining Drills: Should they be a requirement for Electric Mining drills so you could upgrade them as well ?
- Stone/Steel Furnaces: Should there be an upgrade path from "Stone Furnace -> Steel Furnace -> Electric Furnace" to encourage people to craft Steel furnaces rather than leaping right ahead to Electric Furnaces?
- Iron Chests: Should they be a requirement for Steel Chests so they can be repurposed later on?
- Personal Armor: Should each tier of armor be a requirement for the next so it makes sense not to skip ahead? (Thanks to bobingabout)
- Disassembling: Or should there be a more general way to disassemble items and gain back some of their initial resources once they have outlived their usefulness?