I love how the N is in the negative space and the rest of the lettering is the same. It really emphasizes the "thinking" aspect of the word think where you literally have to think about where the N is for a slight second when first looking at the word.
The Ultra Linx [This cute graphic also combines two images using negative space to depict a rabbit holding a carrot. the shapes are obvious and appealing, and the logo would work on varying scales. The use of an achromatic colour scheme is effective in creating an immediately recognisable image.]