What in the DMG is actually al that essential that isn't in the Players handbook? I mean i looked at the NPC classes and the prestige classes, looked at the traps, and took a quick check of the enviromental hazards and like hunger and such.
The DMG is mostly advice, treasure lists, and XP. But there are a few valuable things tucked away in there:
PAGE 19-20: Diagonal movement, extended reduced speeds for encumbrance, aerial movement. Chase rules (don't get too excited).
PAGE 21: Bonus types.
PAGE 22: How to start encounters.
PAGE 28: Weapon size (extended charts).
PAGE 36-41: XP Awards.
PAGE 51-56: Treasure.
PAGE 59-62: Detailed rules for walls, floors, and doors.
PAGE 63-64: Detailed rules for stairs, bridges, pillars, tapestries, and pools.
PAGE 66: Cave-ins.
PAGE 67-76: Traps.
PAGE 76: Yellow mold, green slime, brown mold.
PAGE 86: Wilderness exploration rules.
PAGE 87-92: Detailed rules for forests (forest fires), marshes, hills, mountains (avalanches), deserts (sandstorms), plains, aquatic (underwater combat). All of this is more useful than you'd think.
PAGE 93-94: Weather.
PAGE 99-100: Siege engines.
PAGE 101: Cost to buy a building.
PAGE 104: Cohort and leadership rules.
PAGE 105: Cost of hireling services.
PAGE 107-126: NPC classes and pregenerated PC classes.
PAGE 127: NPC gear value.
PAGE 137: GP limit for towns.
PAGE 145-147: Asian, Renaissance, Modern, and Futuristic weapons.
PAGE 147-169: Planar Exploration rules.
PAGE 169: Alternative ability score generation.
PAGE 176-197: Prestige classes.
PAGE 199-206: Special cohorts, familiars, mounts, and animal companions.
PAGE 206-210: Epic characters (bleh).
PAGE 211-288: Magic items.
PAGE 289-299: Special Abilities
PAGE 300-301: Conditions
PAGE 302-303: Environmental Effects