Walter Mossberg gives it an excellent review:
Overall, Tiger is the best and most advanced personal computer operating system on the market, despite a few drawbacks. It leaves Windows XP in the dust.
It also adds to the Mac’s general superiority over typical Windows computers as the best choice for average consumers doing the most common computing tasks. Apple’s hardware already was the best in the business, and Mac OS X has, so far, escaped the virus and spyware problems that plague Windows.