An ingame modeler/scripter/mapper that is easy to use.
A mod that lets you make a 'vzone' with special Vehicle bricks, and when you finish you delete the 'vzone' and the bricks turn into a vehicle. CUSTOMIZATION HEEEEEECK YEAH.
A mod that will make Trader or someone finally finish JVS elevators, or even better, just JVS elevators .-.
Voice-to-chat. Also heck yeah.
Chat-to-voice? Iunno. "I IZ MIKROSAWFT SAYUHM."
An instant kicker for people who disobey rules =3 (Blockbot for servers much)
Ability to disable flood protection. (Man, that's SO annoying, and the only way to disable it is to give everyone admin.)