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 take a look at some of our top-ranked mutual funds with the lowest fees.

TCW Relative Value Large Cap N (TGDVX): 0.85% expense ratio and 0.6% management fee. TGDVX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With annual returns of 13.89% over the last five years, this fund is a winner.

Goldman Sachs Capital Growth R (GSPRX) is a stand out amongst its peers. GSPRX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks. With five-year annualized performance of 11.4%, expense ratio of 1.25% and management fee of 0.69%, this diversified fund is an attractive buy with a strong history of performance.

American Funds New Economy A (ANEFX Quick QuoteANEFX - Free Report) is an attractive large-cap allocation. ANEFX is a Global - Equity mutual fund investing in bigger markets like the U.S., Europe, and Japan; these kinds of funds aren't limited by geography. ANEFX has an expense ratio of 0.71%, management fee of 0.36%, and annual returns of 12.5% over the past five years.

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.