Which weapons deal splash damage?

Question

I notice that Gaige the Mechromancer's Close Enough skill doesn't penalize splash damage. So, which are all of the weapons that deal splash damage?

Answer 1

From http://borderlands.wikia.com/wiki/Elemental_Damage:

All elemental weapons can do splash damage that affects any targets in that area

Additionally damage over time can spread from one enemy to another nearby, e.g. if a bandit gets close to another bandit who's on fire, there's a chance that he'll catch on fire too.

Explosive damage behaves slightly differently as it has an instant area of effect. I don't think other elements on area of effect weapons such as grenades and launchers cause additional splash damage on top of the AoE, but the DoT effects certainly can spread.

Answer 2

Splash damage weapons can are usually Torgue-manufactured weapons:

In Borderlands 2, explosive damage is largely exclusive to Torgue-manufactured products. However, several other manufacturers feature weapons that deal explosive damage in some manner. They include:

• Assault Rifles that use Torgue barrels (Bandit, Dahl, Jakobs, and Vladof)
• Rocket Launchers (Bandit, Tediore, and Vladof)
• Cobra sniper rifle
• Tediore non-elemental weapons (when reload-thrown)
• Bouncing Bonny, Bouncing Betty, Jumpin Bitty, and Jumpin Biddy grenades
• Grenades and Gurnades
• Murrv, Mrvur, and Muvr grenades
• Kiss of Death grenade
• Singularity Grenades
• Transfusion Grenades
• The Cradle shield (when depleted and discarded)

Source: http://borderlands.wikia.com/wiki/Elemental_Damage#Explosive_Damage_Exclusivity