A decent and moderatw type of mod is the Paintball mod in the realm of Minecraft. This has come with Minecraft version 1.6.2 and 1.5.2.
This mod adds a few fresh items to the arena: a remote, full sets of armor, scanners, insta-bases, flags, pistols, shotguns, assault rifles, snipers, launchers, grenades, claymores, c4, pellets, pods, armor racks, weapon racks, med kits, and paintbrushes in all the colors of the rainbow.
Screenshots:

Items

Armor
Recipes:

Armor

Weaponry

Pellets

Others
Installation:
- Download and install Minecraft Forge installer
- Download Paintball Mod
- Extract the “Paintball.zip” it contains into the “mods” folder of your Minecraft directory.
- Play Minecraft
Downloads:
For 1.6.2
For 1.5.2:
Paintball Mod for Minecraft 1.6.2/1.5.2,