Item comparison too on wowhead.com

[Vitandus]

http://www.wowhead.com/?help=item-comparison

Very nice as it allows you to compare two or more items for a specific build.

[wildcard]

Wowhead also has item weighting now, so list gear for you based on critera you enter.  They even have some preset scales already listed for the basic builds.  Very useful.

[One Ear]

Yeah, highly recommended.