We've been replacing regular bulbs with the halogen bulbs. They are supposed to be much more energy efficient and are brighter. The brighter part I can attest to, how much energy it saves overall, I'm not sure. Because we've finished the basement ourselves, we've just installed the halogen bulbs from the get go which was nice. But yeah, they produce a nice bright, white light.
On a side note, if you have a motion detecting light switch as I used to have in my room, it will eat the halogens for breakfast, lunch, and dinner.