Listmania!
Intermediate Gamer Necessities
By an Amazon.com customer
Polyhedral 7-Die Translucent Dice Set - Smoke with RedPolyhedral 7-Die Translucent Dice Set - Smoke with Red
Buy new: $4.48
You need your own dice, pick your favorite color or weight or just dice that feel lucky. Gaming without your own dice is only acceptable if it is your first game. Expirienced gamers tend to get a little peculiar about letting others use their good dice.
Chessex Dice: Velour Dice Bag Large (5 x 7) - BLACK - Holds Approximately 90-100 DiceChessex Dice: Velour Dice Bag Large (5 x 7) - BLACK - Holds Approximately 90-100 Dice
Buy new: $2.69
If you've got dice you need a bag. Nothing too fancy, but you want to keep your dice together so you don't lose your d4 between games.
Dungeons and Dragons Core Rulebook Gift Set, 4th EditionDungeons and Dragons Core Rulebook Gift Set, 4th Edition by Wizards RPG Team
Buy new: $66.12 / Used from: $53.98
You need your own copy of the game by now as well. You may not have to bring it with you unless you are running the game, but having your own copy means that you can build your character ahead of time and help the newer gamers fill in the minor details of their own characters
Dungeons & Dragons Character Record Sheets: Roleplaying Game Character Sheets, 4th EditionDungeons & Dragons Character Record Sheets: Roleplaying Game Character Sheets, 4th Edition
Buy new: $9.95 / Used from: $2.96
Buying character sheets is really unnecessary unless you are a million miles away from a Kinkos or a printer, but hey, if you have invested a lot of time and playing into a character maybe buyign these sheets is worth the dough.
Dungeons & Dragons Miniatures Starter SetDungeons & Dragons Miniatures Starter Set
Buy new: $69.99
A few tabletop games use miniatures and if the one you are playing in happens to be one you may want to bring your character piece with you.
Dixon Ticonderoga 13872 Woodcase Pencil, HB #2, Yellow Barrel, 96 per PackDixon Ticonderoga 13872 Woodcase Pencil, HB #2, Yellow Barrel, 96 per Pack
Buy new: $15.08 / Used from: $13.99
May as well stock up on No. 2 pencils. A character sheet filled in with ink is a character sheet that is worthless after one session.
Mead Spiral 1-Subject Wide-Ruled Notebook, 1 Notebook, Color May Vary, Assorted Colors  (05510)Mead Spiral 1-Subject Wide-Ruled Notebook, 1 Notebook, Color May Vary, Assorted Colors (05510)
Buy new: $2.54
Have a notebook handy to keep notes about your character on hand. You can't expect someone else to remember that you threw a duck in your bag of holding or that the last time you played you tried and failed to hit on every bar wench in the city.
Varsity Disposable Fountain Pen, Medium Point, Black Barrel/Black Ink PIL90010Varsity Disposable Fountain Pen, Medium Point, Black Barrel/Black Ink PIL90010
Buy new: $0.69 / Used from: $5.00
I know what I said about pencils, but that doesn't mean that pen doesn't come in handy. Writing notes in pencil usually becomes hard to read as time goes on. So for numbers use pencil, for notes use pen.