I see there are all ages. But some seem most surprising.
Is there a “best” age?
I’ll go out on a limb here and say that the smartest people who post to this board are 30.
I’d have to say there is no “best age” here. I’m frequently amazed by the eloquence and maturity of some of the “rotten teenagers” 
who post here. Likewise, I am also frequently amazed by the utter stupidity and lack of maturity of some of the adults who post here (Well, they say they’re adults. These people are known as trolls, sockpuppets, etc. and usually don’t last too long. Unless, of course they continue to keep reregistering because they have nothing else to do with their pathetic lives besides annoy people and piss them off, but I digress.)
That is correct! How did you know? But to be more precise, it’s thirty years and nine months and several days.
<Pointedly ignoring Strainger>
Mu Mu, there doesn’t seem to be a best age. There may be a demographic lump at about 30, but that may reflect a required comfort level with computers mixed with the maturity to enjoy it here.
So exact? This sounds like the voice of experience.
dropzone - for me the “comfort level” isn’t with the computer but the chair. I have to get up and stretch before I’m really done reading.
Phage, you do realize, don’t you, that this means you will be be over the hill within a month?
The benchmark changes with time, obviously. I was quoting today’s figure.
Strainger sez:
I’m frequently amazed by the eloquence and maturity of some of the “rotten teenagers” who post here.
Why, thank you! <curtsies>
<g>.
“Pray, do not mock me:
I am a very foolish fond old man,
Fourscore and upward, not an hour more nor less;
And, to deal plainly,
I fear I am not in my perfect mind.”
–King Lear, Act 4, Scene vii
To answer the OP, don’t know about a best age, but agree that 30 or so seems to be about average.
I’d say being in the computer age helps.
Chef Troy told me my breasts had to be perky to be accepted. That isn’t the same as age, of course, though I’m finding it does have some correlation.
[puts shoulders back and takes deep breath to help breasts in the fight against age and gravity]
It depends–do you mean physical age, or mental age? I think you have to be old enough to realize that it isn’t cool to type in all caps or all lowercase, and have a ability to spell basic words, but other than that, hey, ages 8 to 88 are welcome. But don’t expect everyone to watch their language.
It does seem that there is a wide range of members here and it does add to the conversation. If you can hold your own in a conversation then I guess you are the proper age.
I’m 20. Take that information and do with it what you must.
Oh, please. Everyone knows that the best Dopers are the twenty-three year olds. Anyone who says otherwise is living in a dream world. Try to be kind and humor them. We have to drink quite heavily to tolerate all the kids and old farts. It ain’t easy being this cool.
I’d say as long as you are more mentally mature than an advanced tool user then you’ll fit right in.
I would have to agree with the 20 year old crew. We’re young, smart and able to make references to the current pop-culture that you old farts just wouldn’t get…
I’ll agree with that one. Course, I’m 23 
I thought the same way when I belonged to the twenty year old crew. Now I am old enough to realize that I was mistaken.