I buy cheap 100w/90w Super White bulbs on eBay for $5.50 a pair plus shipping (plus $6 shipping). They are cheap enough that you can keep some spares in case one goes out. I've found that it gives you the most bang for the buck. Here's a link to the seller... he has bulbs for sale all the time:

http://cgi6.ebay.com/ws/eBayISAPI.dl...&since=-1&rd=1

http://cgi.ebay.com/ebaymotors/ws/eB...category=36476

I've been using this type for over 2 years. They have a bluish tint, however the extra amount of light and low cost makes them worthwhile in my opinion.

-- John