Simple is generally the way to go with avatars. Too bad @ShadowFacts wasted his creative talents on a stupid cat! 
Stupid, perhaps, but a lot less slobbery than yours 
And not nearly as friendly looking.
Cat fight!
Doesn’t bother me. I’m just happy that someone noticed me. I’ve been here for about 20 years, and I’m sure that I still fly under the radar to many people.
Nah, I’m sitting this one out.
Besides, cats (and cat people) don’t need approval, they already know they are superior. Just ask my cat.
But the bold black and white image perfectly captures the haughtiness, treachery and calculating evil that is the hallmark of all cats.
The purpose of the avatar, for me, is so I can instantly recognize who is talking w/o reading their names, so a simple portrait, many times in side profile, tends to be the best avatars, as do cartoons. My eyes suck so I don’t really see the detail in some avatars, so faces, shapes, and cartoons are the best for me.
@wolfpup, @octopus, and @BippityBoppityBoo have avatars that fit the above purpose, as do others in this thread.
Which still puts them well ahead of many humans.
While I definitely like it that people are trying to have clear avatars, for me not too big a deal if the avatar is unclear, as long as it seems unique. Sure, if it’s related to your username, or something iconic, it might make you a bit easier to remember, but the main thing is just that I get something visual to associate with you.
I may not have noticed that @Superdude’s avatar was Weird Al (I thought the hair was a hood, making me think “druid,”) but I associate that triangular shape with those colors with him.
It’s also not too huge a deal if you change avatars, as long as not everyone does so all at once. The name is still there, same as someone with a new haircut still has the same face.
Welcome to The Straight Dope!
Woah! That’s some ug-leee cats!
I know one of you looks familiar but your avatars are almost identical, so I can’t decide which of you it is. I think the whole something on top of the head thing is throwing me off.
Never knew anyone who shaved their head have you?
Am I the only person who takes facial avatars at face value, i.e. if your avatar is a face, I assume it’s YOUR face?
I wonder who owns the eyebrow in @RivkahChaya’s avatar?
If it looks like a snapshot, yes. If it looks like an old photo, I assume it’s someone famous(broadly or within a certain field).
If it looks professional, I assume it’s stolen and you’re a spammer.
Even if it’s the face of a hippo?
At first I was exactly like @panache45; I 100% assumed it’s the real person unless I immediately recognize it as somebody famous.
But I’m pretty clueless about faces of famous people. e.g. We have regular users using pix of Hunter S. Thompson and Richard Feynman. I could easily give you a potted bio of either celeb, but had no hope of recognizing their picture. And didn’t know who those pix represented until the user told me/us. Now if the pic was John Wayne or Richard Nixon I’d get that right away.
As more and more Dopers have switched to pictures of people I’m re-calibrating my expectations to match @running_coach’s rubric.
If not her maybe it’s the real person behind @Eyebrows_0f_Doom? That is one very potent eyebrow!
Well, now that I’m reaching a certain age, I have a beard now, and I’ve been living largely as a hermit for the past 15 months, it’s not that far off. 
It may be…from a certain point of view.