Getty can be very expensive. I only use them for higher end clients. I use istockphoto almost exclusively for my own sites. I also pick up stock photo cds ocassionally. They can be a good value. Ignore the clip art that most of them come with.
The one mentionned by Design Agent (http://www.sxc.hu) is great! I use it myself since over a year now. It is free and pictures have good quality.
I'd recommend http://www.sxc.hu/ if you're looking for completely free loyalty-free photos. The images are not as professional as the paid ones, but some of them are very good. As for a paid resource, I'd say matton.com.
At least for me, taking pictures is half the fun ... so don't forget that route. For instance, last week, I was in Seward Alaska on a fishing charter for a major slayfest ... and it was fun shooting pictures of my family and then re-living the moment ... plus I got some great pictures of fishing if I ever have a need for 'em! ;-)
I live near a community college with a good photography program. The kids taking classes are often pretty good and very reasonably priced while they are trying to establish themselves. Some of them will even take some stock photos in exchange for a credit on your website. Katelyn