The burning Soldier - you check his health, and he has enough to survive the afterburn...
The burning Scout - he's bouncing around spamming 'Medic!' and will surely die from the afterburn, but he should be quick enough to reach a health pickup or dispenser if he leaves now...
The burning Spy - he's been lit up by a Pyro and will certainly die if you don't heal him...
The Heavy - if you stop overhealing him, the combined enemy fire will bring him down and the enemy will advance towards you...
The burning Medic - he has 75%+ Ubercharge, while you have much less... if he heals the Heavy and you heal him, you will all live...
A Sniper with Sniper Rifle. There is clearly a problem with the enemy team not being sniped enough that only an additional Sniper can solve...
A Medic, because you understand that every team needs at least 1 Medic to keep the troops alive and deliver Ubercharges to crush the enemy
A Huntsman Sniper! You will wade into the thick of the battle with your Huntsman bow and call for a Medic as soon as you get wounded
Another class other than Medic/Sniper because you only ever play as that class and nothing else.
A Backburner! You attempt to get behind the enemy with cunning ambush attacks to make full use of your 100% rear-crit capability... on an offensive team somehow...
A Flamethrower! You use this to blow rockets back at Soldiers and blast enemy Ubers in the air
A Backburner, which you use to rush into multiple enemies and set them all on fire, perhaps if a friendly Medic would ubercharge you
A Flamethrower! You use this to blast sticky bombs away from sentries and doorways, turn grenades into friendly grenades, blast rockets back at soldiers, seperate Medics from their heal buddy, blast ubered players into the air so a sentry can knock them into orbit, and extinguish burning teammates... oh, and to spycheck everybody, especially around your sentries
A Flamethrower, because you're the only person on the planet who hasn't unlocked the Backburner
You find a Demoman, watch him run out towards the Sentries, then hit the Uber 3 seconds later after he's dead. You now run around looking for a teammate to use the remainder of the charge on.
You find a Demoman and watch him reload his Stickybomb Launcher, then shout "Activating Charge". You immediately hit the uber as soon as he rounds the corner. As he fires at the Sentries, you circle around to draw their fire, staying near enough to him to keep him Ubered.
You find a Heavy, and Uber him when he is 300ft away from the Sentries. He shoots at one from afar while the turtling Engineer keeps the Sentry's health at 99% for the duration. The uber runs out, and the Sentry overpowers the Heavy and he dies. Then you run away.
You find a Pyro (with a Backburner) and uber him around the corner into the Sentry nest. He can't get anywhere near the Sentries due to their combined pushback.
You construct a dispenser and sentry first, making them both level 3. 6 minutes later, you create a teleport exit. Facing a wall. Slowly you upgrade it to level 3.
You drop a teleport exit a little way up the map, facing a wall, where it is clearly visible to enemies. You also drop a level 1 sentry.
You find a hidden, sheltered place way up the map and drop a dispenser, hammer it with your wrench so it builds quickly, then drop an exit which you rotate with right-click so it's not facing the wall. You then ask a teammate to upgrade your entrance at spawn to level 3, while you build a sentry nearby to defend the teleporting players and the teleporter itself
You build a sentry nest where nobody goes and your teammates have to trek a little way to get where they need to be. Your teleport is facing a wall
On the battlements so you can snipe any Demoman, Heavies, Medics etc. that round the corner to push the cart
Around the capture point, hiding behind the sign, sniping the Demoman, Heavies, Medics etc. that round the corner to push the cart
Right outside the right side spawn door, hiding behind the stone wall with only your head exposed and a clear line of sight to the enemy sniper. i.e. here> http://imgur.com/jNc7J.jpg
You fire a few grenades at the enemy while running towards them, expecing the medic to follow you... most of which roll along the floor
You make a sticky trap on the wall with 8 crit stickies
You wait several seconds before realising you have a Kritzkreig, then fire 1 grenade towards the enemy.
You fire stickies at the enemy, detonating each, or grenades if convenient (fire 4, reload, fire , reload fire 1), from a covered position
Believing you are invincible, you rush in firing crit stickies at anything that moves and are cut down by a minigun
All three construct a dispenser and level 1 sentry in random places, while returning to spawn to resupply with metal so they can build their sentry up to level 3
One engineer construct a sentry, which the other engineers will all upgrade to level 3 as quickly as possible. Repeat for the next engineer.
Get those teleport entrances back up!
We're doomed! Quick! Switch to Pyro so we can burn them off our capture point!
Get your bottle out and try to mash him up
Run backwards while firing and detonating sticky bombs in his path
Switch to grenade launcher and fire grenades directly at the Pyro
Switch to grenade launcher and fire grenades at the ground
Placing your teleport entrance on the sloped surface outside spawn, so everybody gets stuck on it when they respawn...
Building a sentry up to level 3 and not having a dispenser. At all.
Repairing other Engineer's buildings when they become damaged...
Never dropping a teleport exit