I prefer not to delete apps that came bundled with Mac OS X. It could cause problems with Software Update. Also, there are a great number of threads where people have deleted such apps, only to come back later and ask how to reinstall them. The space saving isn't worth it.
If you don't want to see them, create an Apps folder and fill it with aliases to the apps you care most about. Then use that folder on the Dock, instead of the Applications folder. You see fewer apps, but no apps are moved from their original installed location.