Just posted one to my blog. There are so many schools of thought, but given your limited time frame, I would suggest either ground chuck or cubed chuck, and if you store carries any dried anchos or new mexcian or chipoltle chiles, grab them. You can use a store bought chili powder (yuck, but it will do) and kick it up with the ground dried chiles. Cut them open lengthwise, remove the stems and seed, toast them in the over for 5 minutes at 350, and then run them through a blender/food processor to make a powder.
The ancho (plobano in it's fresh form) is mild. The New Mexican is about twice as hot and the Anaheim (which is what they call the same pepper when it's grown in CA) and the chipolte (a dried jalepeno) has a big kick with a smokey flavor - use it sparingly.
Add some fresh jalepenos since most stores carry them.
Cook the meat low and slow for at least 2 hours.
Leftover brisket makes for a great chili (learned that from one of the LI Brethren)
IMO, a great chili starts with real chiles.
La Caja China #2
Weber 22 Kettle
Brinkman Vertical Charcoal (out on loan)
Weber Q 200
Weber Summit Series Gasser
super sneaky thermapen disguised as a protemp