Land Raider

The Land Raider is the toughest assault vehicle the Adeptus Astartes have in their arsenal. Like the Predator tank, it can be out fitted with different weapons for various situations. The standard land raider is massive land transport that is able to carry 12 elite terminator marines, unlike the rhino or razorback that can't transport terminators at all, and is able to equip 8 armaments, 3 on each side, 1 for the hatch gunner and one up front. Depending on the chapter or the circumstances, land raiders come in various types and are used in different tactical ways.
Unlike other tanks in the Imperium, the land raider has the power of the machine spirit. A artificial entity that is worshiped by the Adeptus Mechanicus .  This spirit increases the battle effectiveness of the land raider astronomically. In most cases the machine spirit increases firing accuracy of all weapons and/or helps keep the vehicle together when heavy damage is inflicted.

Land Raider Variant types.

Land Raider Redeemer
First created by the Fire Lords chapter, the Land Raider Redeemer was produced to help in long drawn out engagements. When the enemy is entrenched  and you need a weapon to effectively counter such opposition, the redeemer is called upon. The redeemer is equipped with two side flamers and duel front bolter that vaporized any enemy foolish enough to be in its path. This variant is making its first real  appearance  in Dawn of war 2 retribution.

 
Land Raider Crusader
The Crusader variant was designed to tackle strong fortifications and enemy heavy armor. This type of land raider was originally designed by the Black Templar chapter and was so successful it has become a standard variant among most space marine chapters. The Crusader is equipped with three duel link lascannons on each side and the standard front duel bolter. With the increase of firepower the Crusader was out with extra cargo hold to fit the extra generators for the lascannons. Thus this variant can hold up to 16 terminators at a time.
 
Land Raider Achilles
Designed by the Imperial Fists, this land raider was forged to deal with heavy engagements with xenos. This type of land raider is very rare and isn't seen often out side chapters associated with the Imperial Fists. What makes this variant so unique is what is metal is made from and the weapons it wields. Unlike other land raider the Achilles armor is made up of a rare metal that is able to shrug most anti-vehicle weapons like melta bombs. Also it is equipped with a thunderfire cannon, a very power weapon that fire various assortment of ammunition depending on the situation.