The Generic Antagonist Sheet is a DM/GM resource for creating an antagonist quickly, or even on-the-fly during a game. It's intended to be printed out and stuck in a binder.
This sheet has just the absolute minimum stats you need to run combat with a character. In fact, this sheet explicitly lacks stats that vary significantly by race (such as speed and resistances); I trust you to think those up on the fly if you absolutely need them. Besides basic stats for regular and elite antagonists, the sheet includes common damage dice rolls for each tier and a list of common power effects.
This sheet is also available as part of a large torrent file called Third Party Materials Collection for D&D 4th Edition