There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

The easiest way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

Let's break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

ASG Managed Futures Strategy Y (ASFYX Quick QuoteASFYX - Free Report) : 1.48% expense ratio and 1.25% management fee. ASFYX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. With annual returns of 8.82% over the last five years, this fund is a winner.

Black Oak Emerging Technology Fund (BOGSX Quick QuoteBOGSX - Free Report) is a stand out amongst its peers. BOGSX is part of the Sector - Tech mutual fund category that invests in technology and lets investors own a stake in a notoriously volatile sector, but with a much more diversified approach. With five-year annualized performance of 13.48%, expense ratio of 1% and management fee of 0.74%, this diversified fund is an attractive buy with a strong history of performance.

DFA US Large Cap Growth Institutional (DUSLX Quick QuoteDUSLX - Free Report) . Expense ratio: 0.18%. Management fee: 0.15%. Five year annual return: 12.48%. DUSLX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.