XENSE is a very stylish theme and great for your portfolios! You can also use this theme in a website made with another theme, just to show your images fullscreen. The Xense theme resizes images to fill browser while maintaining image dimension ratio. Adding images is really very very simple with the free Slider stacks or snippets. There's an example snippet with links to three tulip images in the downloadfile, so you can start immediately. The content is located bottom-right, and both its width and height can be adjusted.
There are 4 themes in the download file (a normal, a YouTube and Flickr version) all with an animated query menu menu. The Flickr version that pulls all images from Flickr.
April 2013: Added the (NEW) XENSE-Responsive theme!