Furniture: Large, comfortable furniture such as a leather recliner or a long, cushy sofa makes it easy to stretch out, kick your feet up, and even nap. A few muscular pieces of furniture will be more effective than several wimpy ones.
Fireplace: Even if it doesn't burn real logs, a fireplace adds warmth and visual attraction to the room and makes a fine focal point for any guy room.
Electronics: Don't hide the high-tech. Whether it's a flat-panel big-screen TV, DVD player, sound system, or computer -- electronic gadgets should be visible and accessible. Don't bother trying to conceal the TV in an armoire or the computer in a rolltop desk. Let an attractive entertainment center dominate one wall, or devote one corner to stylish office space. And -- perhaps most important of all -- whatever you do, don't hide the remote control!