This is your red-letter day, dear reader. If you hadn't happened on this article, your life might have unraveled in a most unfortunate way. You might have -- gasp! -- invested in mutual funds!

As Shakespeare would have said, "Heaven forfend!"

I'm here to steer you straight -- away from dastardly mutual funds and toward more sensible investments. Such as ... well, I'll think of some soon. In the meantime, let me try to name the countless drawbacks of mutual funds.

Diversification
If you invest in a mutual fund, you'll instantly be invested in, say, 50 to several hundred stocks (or bonds, or what have you). Invest in a broad-market index fund, for example, one based on the S&P 500, and you'll own a stake in 500 of America's biggest companies, such as Honeywell (NYSE: HON), Nabors Industries (NYSE: NBR), and Hershey (NYSE: HSY). Over many decades, the S&P 500 has averaged annual gains of about 10%.

That's nice, but an average of just 10% per year? Sure, that's more than the long-term average gains of bonds and real estate and lots of other things. But come on, you gorbellied, knotty-pated hugger-mugger -- that's playing it too safe!

If you invest all your money in just one or two stocks, you might do much better than 10%. Best Buy (NYSE: BBY), for example, sports an average annual return of 28% over the past 20 years. For Procter & Gamble (NYSE: PG), that average return is 17%, and for Tiffany (NYSE: TIF), 16%.

Of course, not every company fares as well. Radio Shack (NYSE: RSH) has averaged a little over 3% over the same period.

Professional management
Some favor mutual funds because they allow trained professionals, some with sound ethics and deep insight, to invest your money for you. Well, I suppose that's fine -- if you're a fobbing, clay-brained measle.

Don't you have any respect for yourself? Do you really need someone else to manage your money? I suppose you don't pull your own teeth, either, preferring to leave that to a "professional." And how hard is it, really, to rewire a house? Electrician, shmelectrician.

Low cost
OK, so mutual funds, at least the good ones, don't cost too much. Investing advisors can take 2% or more of your assets each year -- plus a share of your gains -- in exchange for their professional guidance.

Some index funds charge less than 0.25%, while many well-managed mutual funds charge around 1% or less. If you wanted to buy 20 companies on your own, it wouldn't be cost-effective to do so unless you had many thousands of dollars. But with mutual funds, you can spread as little as $1,000 or less across many companies.

Of course you could put all your money in one stock. Sure, it's risky, but it won't cost you much, relatively speaking. If you plunk your entire $50,000 investment into one stock, the brokerage commission might be just $10 or $25 or $50. That's peanuts. There's your low cost, you yeasty, bat-fowling coxcomb, you.

Dollar-cost averaging
Oh, you just want to have your cake and eat it, too, don't you, you puking, ill-breeding canker-blossom? You want to be able to add to your investments regularly over time, without incurring copious commission fees? You like that you can regularly invest in a few mutual funds painlessly and inexpensively?

Fine. Suit yourself, you droning, rude-growing pignut.

My simple plan of putting it all in one stock makes dollar-cost averaging easy. If you're just plunking in $25 at a time and paying a $10 commission to do so, though, you're not doing yourself too many favors.

More "advantages"
I know. You can cite other so-called advantages of mutual funds. They make record-keeping easier, for example. They're very liquid, meaning you can cash out quickly if you need to (as opposed to, say, real estate).

There's even a wide array of funds to choose from, including many that focus on companies by size, geographic region, industry, social responsibility, growth, or income. Go ahead and dwell on these if you want, you infectious, swag-bellied vassal.

And you, too, my Fool colleagues, you frothy, pox-marked gudgeons. Yes, you who write alongside me.

I know that many of you look kindly on mutual funds. I know that we even launched a newsletter service several years ago dedicated to introducing investors to some "top-notch" mutual funds out there. I suppose there's some sense to that, since many weedy, half-faced mammets will still opt for mutual funds, no matter how much common sense I try to beat into them.

So go ahead, you beslubbering, flap-mouthed harpies. I invite you to sign up for a free trial of our Motley Fool Champion Funds newsletter, which offers regular fund recommendations monthly in an easy-to-digest format. Its picks are beating the market handily (28% vs. 10%, last time I checked). A free trial gives you access to all past issues, so you can read about each recommendation in detail. You goatish, earth-vexing nut-hook.

This article was first published July 16, 2007. It has been updated.

Longtime Fool contributor Selena Maranjian owns shares of no company mentioned in this article. She tapped the services of a Shakespearean insult generator for this article. Best Buy is a Motley Fool Inside Value and Motley Fool Stock Advisor recommendation. The Motley Fool is Fools writing for Fools.