There was a recent thread about this very same issue. Sylvania SilverStar Ultras are brighter at the expense of lifetime. So far as I can tell, ANY "brighter" 55 watt bulb does so at the expense of lifetime. If you stay with conventional halogens, Sylvania Long Life or Phillips equivilant would be your best choice.

Many on this forum (see previous poster) are switching to very reasonably priced HID kits. $70 - $150 per pair. They are much brighter, and supposedly last 10 times longer. I love mine.

Do a search on "HID" and you'll find a fund of knowledge!