Santa Gears

Set the system date to December 25. All the Gears will wear Santa Claus hats.

Guided Weapons

These include some indirect weapons ( mortars ) and missiles ( AGM and ATM ). These are not that useful during conventional missions, unless you are a really poor shooter. However, the AGMs can be extremely useful for taking out enemy frames in the zero-G missions towards the end. It's not that easy to aim when both you and your target are moving through space.

Vibro-axe

You'll get to test this out in the mines. Powerful hand to hand weapon.

Automatic Weapons

Great for using against enemy gears in brawls ( short / mid range battles ) because these things can fire nonstop. The anti-air cannons and autocannons are similar but the anti-air cannons have a higher fire rate. The Very Heavy Autocannon ( VHAC ) does the most damage of these weapons, and is quite nice for shredding gears at short-mid range.

Rocket Packs

Good for people who can't shoot straight. Actually, these can be quite useful if you want to level out a large area ( say an enemy blockade ) and you don't want to have to pick of the infantry one at a time. Use this to fire into a crowd of bad guys.

Heavy Bazooka

This can be used as a demolition weapon. It also comes in handy when you want your target dead immediately. Because it takes a while for the projectile to reach its target, it's most useful either on stationary/slow moving targets or as a short/midrange weapon. Also useful if you want to destroy your target in as little time as possible. This can also act as a demolition weapon. This weapon is not very forgiving -- miss an enemy and you could accidently nail one of your squad mates. If you need more ammo than the heavy bazooka permits, the medium bazooka is almost as powerful, and you can carry much more ammo ( as much as you'll need ).

Rapid Fire Bazooka

Personally I prefer the Heavy bazooka but the idea of a fully automatic bazooka is too cute to go unmentioned. This weapon is fun.

Heavy Pulse Laser Cannon

This and other energy weapons are great for long distance shooting because there's no delay between you shooting and the target getting hit. The energy weapons are quite nice for sniping -- if you have a good dose of the stealth perk, you can shoot with this weapon without your target spotting you ! These weapons are not only accurate, but they are truly "stealth" weapons. The HPLC is powerful if you can shoot straight. 2 good hits will take out enemy gears/frames. If you're in a Cheetah or one of the heavy family, you only get 80 rounds of ammo. That's usually enough. If you need more, go with a lighter energy weapon.