INFANTRY

Light Infantry

Lightly armored and can move over almost every terrain type. Armed with a M16 Mk. II pulse rifle, they deliver light damage to most targets. Although slow, they are capable of moving over varied terrian types with little loss in speed.

Cyborg

This unit is part human, part machine, and is armed with heavy body armor and a high power pulse rifle. Two Good things: it will heal if standing in a Tiberium field and it cannot be run over.

Rocket Infantry

The Rocket Infantry is a rather versatile unit. It carries a rocket launcher. This unit is able to fire at both land and aerial units but is very slow. The Rocket Soldier is mainly geared towards armored vehicles and buildings. He does not fair well against other infantry.

Chemelion Spy (not implemented into the game)

This unit is virtually invisible thanks to a smaller version of the Stealth Tank's Lazarus Shield. It is only slightly visible when moving. When you infiltrate a building with the Spy, he randomly copies plans for units, structures, and other secret information from the enemy's base. Beware of GDI's MSV though, for that is the only unit capable of seeing the Chemelion.

Field Mechanic (not implemented into the game)
This unit is used for repairing damaged vehicles on the battlefront. Since NOD does not have a Repair Depot (or service Depot...), and you would like to be able to repair units, I suggest you have one of these little babies on hand. Keep this unit closely guarded because it does not have a weapon (well, maybe a wrench... lol).

Engineer

The engineers are back to normal, the way they were in the original C&C, they take over buildings no matter what the health, they also repair bridges and other buildings when told to do so.

Cyborg Commando

The cyborg commando is a badass. He comes armed with a Laser Sniper rifle. He is slow moving and heals when he stands in a patch of Tiberium. This unit is effective against all of the units on the battlefront.

Mutant Hijacker

Another kind of mutant commandos, this unit can hijack any units on the ground he wishes, even a civilian car and then giving the control of the unit to the player. Once in a unit, the hijacker remains in there until the unit is destoyed (then it pops back out). This unit will heal standing in Tiberium.

GROUND-BASED

Mobile Construction Vehicle

The MCV is the MOST important unit in the game. It can be deployed into a construction yard, which in turn, lets you build structures and units. Keep your eye on this unit, even after when it's deployed, because this is the only thing that lets you build structures. No structure leads to no defense, no units, and at last NO victory! Get it? Perhaps the coolest feature in Tiberian Sun that should have been implemented in RA and TD was the ability to deploy back into a MCV. This will allow the player to expand their base without the high-costs of building another MCV.

Attack Cycle

This unit is very effective in scouting because of its fast speed. It carries twin rocket launchers but no armor.

Artillery

The artillery is the longest ranged unit in Tiberian Sun. It also has a very powerful weapon. Hence the name "artillery". It has to be deployed before firing and undeploying before moving. The drawback to this unit is that it is VERY slow. It must be guarded at all times by other units, because it is lightly armored and will be wasted in a close-ranged battle.

Devil's Tongue

This thing will burrow to where GDI least expects it and will incinerate everything not heavily armored. Good for softening up base defenses from the inside out.

Subterranean APC

NOD finally has an APC... this unit will transport your units underground, so you can pop-up at the enemy's base without notice... Very sneaky, but it can't pass the GDI's Mobile Sensor Arrsy (MSA)

Tick Tank

This looks like your average light-armored tank... until it burrows into the ground and doubles its armor, making it a mobile turret. It is perfect for guarding Tiberium fields and choke points. As you've guessed, it can be re-deployed back into a tank.

Stealth Tank

The Stealth Tank in TS is able to cloak itself, remaining undetected to enemies. However, when firing it has to de-cloak (like all other stealth units in TS). The Stealth Tank can be detected by base infantry, base defenses, and GDI's mobile sensor array.

Harvester

The harvester is one of the most important units in Tiberian Sun. This is the unit which gathers a highly toxic mineral called Tiberium and brings it back to the refinery in order to transform it into spendable credits (money). Although it is heavily armored and smarter, keep the harvester under VERY CLOSE supervision. It's very likely to get blown up by aerial units or stealth/underground units.

Weed Eater

This NOD unit eats the tiberium veins, goes and dumps it into Tiberium Waste Facility. Once you get enough tiberium veins, you can launch a Chemical missile, which is loaded with the tiberium which was collected.

Mobile Repair Vehicle

This robotic vehicle will repair your damaged vehicles and aircrafts, for no charge. By placing this unit in guard mode, it will automatically find and repair friendly units.

AERIAL

Harpy

The Harpy is fast and works well against infantry and lightly armored units. For it to reload it must return to the Helipad.

Banshee

Experiments with recovered Nod technology have allowed Nod to develop the next generation fighting aircraft. It carries twin plasma cannons and can take out almost anything when grouped together.

SPECIAL

Hunter Seeker Droid
The Hunter Seeker Droid is acquired when you build the Temple of Nod. When this unit is released, it will randomly search out for an enemy unit or structure on the map. Once attached, it will self-destruct, destroying the object and its surroudings. It cannot be controlled and cannot be destroyed once released (which is VERY annoying).

Montauk
The Montauk is Nod's mobile command center. Commander Slavik and his crew uses this to travel from battle to battle. It's capable of burrowing underground, but it should not be near danger. If the Montauk is destroyed, the battle is over.