I will be voting for Barack Obama. The LA Times endorsement from last week put the "why" better than I can.
In the language of metaphor, Clinton is an essay, solid and reasoned; Obama is a poem, lyric and filled with possibility. Clinton would be a valuable and competent executive, but Obama matches her in substance and adds something that the nation has been missing far too long -- a sense of aspiration.
Here's hoping that you aspire to vote today.