How much is too much when drinking? As in when should one stop in a number.

I usually stop when my knees start to bend the other way.

After you can no longer stand or speak or see ...

Like Gator said, there's no number that will fit everyone. Some people are "lightweights" and can't handle much at all, and for some it takes a lot to effect them at all. I can't drink much myself because I have such a small frame, so I tend not to drink when I'm out, only when I'm home with friends in a safe environment.

If you can't tell when you have had enough, you probably shouldn't be drinking. And there is no magic number that fits everyone. My family and I will go out for a few hours for live music and good food at our favorite restaurant on the river. I stop at three beers. I am done at that point. The rest of my family can do one or two more. And I outweigh most of them.