This week's book giveaway is in the Agile and Other Processes forum. We're giving away four copies of Real-World Software Development: A Project-Driven Guide to Fundamentals in Java and have Dr. Raoul-Gabriel Urma & Richard Warburton on-line! See this thread for details.
Java has a pretty huge support communitiy, and the exams test you on things you work with fairly regularly. I find the db certifications, db2 and oracle, tend to pull out features that are rarely used, and rarely seen in everyday administration.