I have never bought gas from Exxon (or Mobil, since the merger). I didn't drive before the Valdez accident, and I continued my parents' boycott after I started driving. Looks like a bunch of people are coming back to the boycott, in a big coalition called Exxpose Exxon. I wholeheartedly endorse this product and/or service.
The beef is not just ExxonMobil's continued failure to pay punitive damages over the Valdez. They are the last oil company actively lobbying to get in and drill ANWR. They are making no efforts on renewable energy production, and have supported anti-science measures on global climate change.
They fund climate change skeptics, which gives those skeptics the same credibility as tobacco company scientists. Plus, they hired the execrably Phil Cooney, who edited scientific statements about climate change out of Bush administration reports.
Other companies run ads touting their commitment to post-petroleum power sources. Why can't Exxon do the same work?