I think many people use point buy, but I wouldn't say most. There are plenty of DMs out there who use 3d6 (in the order rolled), 4d6 drop lowest (in any order), 4d6 (reroll any 1s and then drop lowest), and even 5d6 (drop lowest 2).
If you like overpowered characters, why not try a 36 or 40 point-buy system. I tend to like overpowered characters myself and am happy with a 32 point-buy system, though.
Another system I used to use until I got tired of always having to deal with a jerk I no longer play with was a system that ignored the "scaling" you get for higher level attribute scores in a point buy system. Here were the rules, feel free to use them:
1. You choose yur own ability scores.
2. They may be any number between 3 and 18.
3. When you are done, the sum of the scores [STR, DEX, CON, INT, WIS, CHA] must be 84.
Now, that system worked great because it allows plenty of play, caps players from abusing it high by saying a score can't go over 18, and the general array people used was: 18, 16, 14, 14, 12, 10. But, I met a jerk who was only about min/maxing. He didn't care about reality nor even roleplaying. He wanted to kill things and only kill things. So, he submitted a fighter one day with the following scroes: STR (18), DEX (18), CON (18), WIS (9), INT (18), CHA (3). While the character was legal, I think you can see playability issues. The player said, "My guy knows he's irritating and ugly because his low CHA, so he just won't talk."
I had to laugh. I didn't really mind the high stats so much ... but our group is all about roleplay. We are about 90% roleplay and 10% combat when we game. This guy wouldn't (and didn't fit). After that, I changed the rules just so I wouldn't have to deal with the situation again. Rule #2 became:
2. They may be any number between 3 10 and 18.
Now, this system still can create some VERY powerful characters. You can tweak the power easily by tweking the number the scores must equal in the end. As an example of the power, the array 18, 18, 18, 10, 10, 10 (54 pt equivalent) is still legit. But I found most of the players went to something more reasonable - like 18, 16, 14, 14, 12, 10 (44 pt equivalent). As you can see, it does add back in flexibility as all characters need not be the same point buy.
But, in the end I went back to using a 32 point buy. It's much more common and people know how to use it already.