There are plenty of army types that you can build in 40k. One of the most hair-pulling and hardest to deal with is the Assault style. One where it's a mad dash to get as many kills under your belt as possible and decimate the biggest units first and finish the fight fast.

Everything from building hopping to massive melee rushes, here are my top 5 Assault Armies in 40k. 

5. Tyranids - Hive Gaunt Rush

Tyranids are best known for their massive wave of Hormagaunts rushing the bigger models while the larger bugs focus on the small enemy models. It works best with around 60% gaunts to 40% Large models like Hive Tyrants.

This makes them super hard to deal with as they can chunk down even the biggest enemies fast.

  Excels in:

• Fast turns and Easy target acquisition.
• Rushing larger enemies which can be the hardest targets.
• Finishing games in under 5 Battle Rounds. 

  Fast Details:

• Super expensive to make a competitive army.
• Hard to move all the Models around the table

4. Adeptus Custodes - Low Numbers High Damage

Custodes can do one thing, and they can do it really well. With their high point cost per model, they make an amazingly fast game Assault squad that can do more than most higher model count armies.

Do you want to decimate a Rhino in 5 hits? You pick Custodes. Do you want that flying T’au ship on the ground in pieces? Custodes. 

  Excels in:

• Insanely low model count, crazy high damage.
• Fast-paced games and Battle Rounds.
• The ability to have your entire army be one unit.

  Fast Details:

• They are going to get swarmed by bigger armies with more models.
• They have amazing shooting potential but the close range is a bit lacking.

3. Blood Angels - Swords with Chainsaws

ChainSwords, enough said. The Blood Angels have one really big thing over any other Legion of Space Marines, melee skill that is astronomically amazing.

Picking an Assault army for Blood Angels is essentially just fitting them to be as fast and as close range as possible. 

  Excels in:

• Close range melee and pistol based fights.
• Using Codex based tactics they can actually get even better in melee.

  Fast Details:

• Without their Codex they are just marines, keep that in mind.
• Build the army to be heavily melee focused but don’t forget a bit of range as well, you don't want to get caught off guard by T’au or Chaos snipers.

2. Chaos World Eaters - Blood For The Blood God

The biggest and best in terms of just shutting down psychic blockades and beating their way through.

The World Eaters have an innate ability for just shrugging off psychic powers and can stampede through pretty much any unit. If you are going to pick the world eaters, be ready for any other player to want to avoid you.

  Excels in:

• Breaking psychic powers through tactics. 
• Melee focused, BLOOD FOR THE BLOOD GOD.
• Very fast units, capable of just speeding through the battlefield.

  Fast Details:

• These are thematic Angry Marines, keep that in mind when putting the army together
• Same as Blood Angels, don't just focus on Melee, you need “some” range in there as well.

1. Raven Guard - Jetting over Everything

Raven Guard, Like any Marine legion, have access to the Inceptors. Inceptors have a Jump-Pack which makes it so they can jump over any terrain in the game and essentially turn a carefully laid out battlefield into a beeline for the enemy front-line. Using them with Raven’s tactics makes them nigh impossible to hit and even harder to kill. This level of play is hard to master but SO worth it when you do. “Fly circles around everyone.” 

  Excels in:

• Jumping terrain to get better shots and close the distance between enemies. 
• The Ravens Fury Tactic makes Jump pack only warfare feel almost dirty.

  Fast Details:

• Your main force is going to be Inceptors at a decent range, use energy weapons for maximum AP.
• Inceptors may be nice, but you’re going to have to advance almost every time you move to get the most out of their terrain hopping power.