bulb advice

[Nick Lawrence]

I currently use Sylvania 9003XV   60/55w bulbs in my "fleet" of Audi's.   Don't seem to get much life from them, maybe a year or less.  All are relayed and powered from the underhood battery post.
Has anyone used other brands and experienced better life?  If yes where can I find them?  Cost wise the Sylvania's are about $18.00 a pair so I wouldn't get too crazy about spending a lot more.
TIA
Nick