jRocket is a Java runtime that was also bought by Oracle, and is targeted at the enterprise crowd:
However, it is available for free, and while it starts programs slightly slower, because it precompiles them, it reportedly runs them significantly faster. They ask a lot of questions about your company, which I just give nonsense answers to, since they don't seem to conceive that home users might want a faster Java. Thus, it is the only Java I use. When I try to run jEdit from the Start Menu on Windows (vers. 4.5), it complains "this application requires a Java runtime environment 1.6.0." However, starting up the jar runs flawlessly.