Banner Image is a great plugin to implement custom banner Image for each page. You can set images easily and later can manage CSS from your theme.

Allows the custom header image to be replaced by the featured image of the current post or page.

Select a specific header or random header image for each content item or archive page.

This plugin is DEPRECATED with WordPress 3.2.

Allows you to add/associate unique header image with each single post/page.So you can spice your blog to have a unique header image per post/page.