Welcome the CPF, torch masta!
The brightest LED flashlight would be some kind of custom built, LuxV (Luxeon V LED) running off lithium-ion rechargeables. It won't be cheap. I think the brightest LuxV production lights are made by SF right now, although other companies are slowly introducing 5W models as well. Don't believe eBay claims of 7W, 8W, or 10W Luxeon lights - those emitters are not in production yet (but expect to see them from SF later this year once Lumileds has them ready).
On the cheaper side of things, but still plenty bright, you can pick up a TerraLux MiniStar2 drop-in module from led-replacement.com About $20 and many, many times brighter than the stock miniMaglite.