21 Investing Principles by Peter Lynch

Peter's Investing Principles:
1. When the operas outnumber the football games three to zero, you know there is something wrong with your life.
2. Gentlemen who prefer bonds don't know what they are missing.
3. Never invest in any idea you can't illustrate with a crayon.
4. You can't see the future through a rear view mirror.
5.There's no point paying Yo-Yo Ma to play a radio.
6. As long as you're picking a fund, you might as well pick a good one.
7. The extravagance of any corporate office is directly proportional to management's reluctance to reward the shareholders.
8. When yields on long-term government bonds exceed the dividend yield of the S&P 500 by 6 percent or more, sell your stocks and buy bonds.
9.Not all common stocks are equally common.
10.Never look back when you're driving on the autobahn.
11. Never bet on a comeback while they're playing "Taps".
12. The best stock to buy may be the one you already own.
13. A sure cure for taking a stock for granted is a big drop in the price.
14. If you like the store, chances are you'll love the stock.
15. When insiders are buying, it's a good sign -- unless they happen to be New England bankers.
16. In business, competition is never as healthy as total domination.
17. All else being equal, invest in the company with the fewest color photographs in the annual report.
18. When even the analysts are bored, it's time to start buying.
19. Unless you're a short seller or a poet looking for a wealthy spouse, it never pays to be pessimistic.
20. Corporations, like people, change their names for one of two reasons: either they've gotten married, or they've been involved in some fiasco that they hope the public will forget.
21. Whatever the queen is selling, buy it. (when the government privatizes a company, buy it).

Source: investorwords.com

This is what I like most.

When even the analysts are bored, it's time to start buying.