When it comes to sizing up mutual funds, performance isn't everything. How much risk did the fund take to earn that return? In rating mutual funds, BusinessWeek looks at risk and return over a five-year period. Funds are given a rating (A through F), and these ratings are updated monthly at BusinessWeek Online (www.businessweek.com/mutualfunds/mutfunds/scorebrd/index.html). The following equity funds joined the A-list in the most recent review.