You can try the in-camera raw processing to be able to have more control over image quality. If you want the best, avoid jpeg. Its fine for ebay and craigslist photos, but for archival work, they won't stand the test of time.
Raw images I took several years ago and processed with Lightroom 2 can be reprocessed with the latest version, and do look much better. You can't do that to in camera jpegs, they are frozen in time, and best used for cases where time is more important than quality.