Command & Conquer/Belgrade

"Fish in a barrel". You're given a small attack force, but the vehicles alone are more than a match for the convoy that wants to speed through here.

The sole objective is to destroy all enemy units. The enemies won't leave the map, but you will have to hunt down those that break through.

Preparation
Head to the right with the mammoth tank, up to the bridge. You may advance him until you barely see the NOD artillery, which won't attack unless fired upon (or activated by moving further). You can optionally flank the artillery by moving other units to the north, but this is not required.

If you want to make an early kill, you can move a few tanks to the far north-west corner of the map, and destroy two artillery units. This is not required, but it slows down the enemy reinforcement rate (see below).

Convoy
The convoy starts to move once you move one unit down the valley. Other parts of the convoy arrive when the enemy reaches certain checkpoints in the north and west approach. Although you could minimize the number of enemies by pressing the attack against this approach, this is impractical due to the reinforcement pattern (which includes stealth tanks.)

The best position is right in the center, as all units need to pass through there whether they approach from the north or west. The mammoth tank can take point, with the tanks and rocket launchers providing support.

The convoy itself starts with four artillery units, starting at the northern road, and splitting into two passages. Reinforcements arrive as the convoy progresses, and can be stopped by rapid kills:
 * Two flame tanks arrive once an enemy unit enters the split. Triggers once per split, with flame tanks taking the other route. Totals four flame tanks.
 * Two light tanks arrive when an enemy unit is almost through the split. Triggers once per split, totaling four light tanks.
 * Two buggies approach if a unit slips past the center, and two more if said unit reaches the right and turns south.

Stealth tanks will also try to slip past. They appear under the following conditions, but are guaranteed to appear:
 * Two stealth tanks arrive if you destroy the initial four artillery units. They take the west path, then hunt down your units when they reach the center.
 * Two stealth tanks arrive once you destroy eight units. Takes the east path, and eventually parks in the south-east region of the map (near the closer tree cluster)
 * Two stealth tanks arrive once you cross the eastern bridge.

When the convoy is eliminated, send a tank to the north east to find the last unit (make sure you have units behind to intercept stealth tanks). Save the game before destroying the last stealth tank.