What mods do you think deserve to be in the game?

Things like Bob's mods are loads of fun, but they might be a little bit too complex for somebody coming in to the vanilla game (at least in my opinion).

I'll start:

• Replacer (helps you convert things like yellow belt to red/blue or small electric poles to medium)
• Blueprint String (There would need to be a few things ironed out, but it would really be something that made it easier for the community to interact more, sharing builds and such.)