Ailaros wrote:
#1.) CCS.

There is nothing this squad can't do. Defensively, you can take 4 BS4 plasma or meltaguns, and put them in a chimera if you like. Offensively, you can take a BS4 lascannon and officer of the fleet for pretty cheap. Plus, they can order themselves to be twin-linked against vehicles or monstrous creatures, and can force your opponent to reroll passed cover saves. That and it's one of the best places in the codex for a power fist, and can come with a "I did an extra wound this round *wink*" upgrade to help them win assaults. This tiny squad can pack a lot of punch for very cheap.

But it doesn't stop there. They are a great support unit, being able to rally broken units (even at less than 25%) with ease, while being able to take an upgrade that lets anything remotely nearby reroll their failed morale tests in the first place. They can make units nearby twin-linked against vehicles or monstrous creatures, and do the faux ignore-cover thing. They can make sure stuff gets a 6 on its run rolls, and give a ghetto version of bolter drill to lasguns nearby.

But that's not all! They also have more meta-influencing stuff, like the ability to reduce your opponent's reserve rolls by 1, or to increase yours by 1 and reroll where your outflankers come in from.

All this for a price tag that starts at 50 points, and rarely exceeds 100. It's possibly, per points, one of the best units in the game, much less the guard codex. It's only a shame that it doesn't quite dovetail with mech lists as well as you'd hope.

#2.) Conscripts with Send in the Next Wave!

They are an invincible scoring unit. Let me repeat that in case you missed it. Invincible scoring unit. Whenever you kill off a couple of conscripts, a few moments later they return to full strength and can teleport to anywhere inside of my deployment zone.

Every game, you just HAVE one objective, more or less, and your opponent is actually WORSE off for attacking them. There is nothing else in 40k even remotely like this.

#3.) Punishers.

Give them a pair of multimeltas and a lascannon, and they create a 30" bubble where they're going to absolutely ruin anything foolish enough to enter. Being a heavy 20 gun, they can handle things that are susceptible to volume of fire. Having two multimeltas and a lascannon, they've got the power to handle anything that isn't. There is nothing that your opponent can bring that gets within that threat range that a punisher can't at least somewhat handle, if not just stomp dead.

It provides great zone control on a really durable chassis, screwing up your opponent's movement in a difficult to dislodge way. Plus, on occasion, they count as scoring units to boot.