Don't think you're the only one clever enough to make a Master Chief outfit.
Every year, eager costume creators pick a few cultural phenomena to drive into the ground. Here's a list of this year's worst offenders.
Michael Vick or his dogMichael Vick is a total douche, but then again so are the people that will be trying to get laughs dressed as his pit bulls.
A less lame option: If you want to poke fun at a former NFL player, try a Pacman Jones jersey and a championship wrestling belt. His pain is your trick-or-treating gain.

O.J. Simpson in a prison outfitThis one wouldn't be too bad if it hadn't already gotten played out back in '95. Plenty of other celebrities have gotten arrested; why not try one of them?
A less lame option: A drunk Kiefer Sutherland might not be a bad choice. The most expensive part of the outfit will be the booze you need to get drunk.

The iPhoneWhen the iPod first came out, only hard-core nerds got dressed up as their favorite gadget, but now the iPhone, the iPod, and their wealthy daddy, Steve Jobs, are as much a part of pop culture as crappy sitcoms and beer commercials. We don't need to see a bunch of hipsters walking around in painted cardboard boxes to remind us how dependent we are on the things.
A less lame option: Join the social and go as a Zune. If you do, Microsoft will probably pay you. Not really.

Tay Zonday (the "Chocolate Rain" guy)More than 10 million people have watched his video on YouTube, and 9 and a half million people are sick to death of it. The other half mil will be sporting horn-rimmed glasses and wraparound headphones on the 31st.
A less lame option: The "I love turtles" zombie kid will be big, but it has a certain subtle charm that Tay Zonday lacks.

Master ChiefThe Chief is actually kind of a cool costume, but with so many turbo-dorks out there creating movie-prop-grade reproductions of the Spartan Armor, casual costume jockeys like us can't compete. That doesn't mean they won't try and fail, though.
A less lame option: Since
BioShock got pushed out of the limelight by
Halo 3, there will probably be plenty of sweet Big Daddy costumes hanging around the bargain bin.