Here are the major ones.
#1: Farm Zombie Classic
This is the first avatar I used after joining KYM. At the time, I was still a brony, so I chose the background pony Lyra Heartstrings giving a funny expression from…this image. It was a different time. I kept this one for about a year and was hesitant to change, but my waning interests in MLP eventually led me to another.
#2: Six Nine So Fine
Pictured is the character Yuudai Chiba from Mitsudomoe, the only anime guaranteed to feature at least one pedophile joke every four minutes. Something about my avatar being a perverted Japanese middle-schooler with a 69 hat just makes me happy.
#3: Clown Motel
One memorable night, Vinny from Vinesauce steamed himself using an Image-to-Image program which let him create realistic images of whatever buildings he wanted. Early on, he drew a face, which resulted in the above image. He called it "The Clown Motel." It is horrible and I liked the idea that it would creep people out every time they saw it.
#4: Glitch Yuri
Doki Doki Literature Club was one of the few times I was an early adopter of something popular. It's a truly clever game and this image was one of the most memorable moments to me.
#5: Degraded Dink
Similar to the Clown Motel image, Vinny was streaming the Pix2Pix program, allowing him to turn his drawings into realistic faces. Chat request he draw Mr. Dink from Doug. This profoundly haunted image was the result.
#6: Sega Saturn
A single image from the greatest video game advertisement ever created. I was one of the lucky few to receive it in the mail as a child, though I have never owned a Saturn.
#7: Redd Greene
My RWBY OC created for Spirit Week.6. I'm pleased with how this one came out and think I'll keep it for a while.
Video games, anime, and ponies. My family is proud. Keep in mind that after I change my avatar, I sometimes keep the old ones around for accounts on different sites, so Chiba and Yuri are still around elsewhere. This lets me keep the past alive.