These are basically products of the RPGamer message boards or #fret, for the most part. Products of late-night #fret, to be more specific. If you don't understand them... well, I don't remember what brought on some of these things either, to be honest. Actually, it makes me laugh harder...

Gilgi - A really terrible movie in which an inept villain falls in love with a fake plastic lesbian. ...Oh wait, Gilgamesh is the action figure in this hack. Still an improvement over the actual movie!
New, from Glico! - A new flavor of Pocky, just for Ren! ...Yeah, I was bored, and not feeling quite right in the head. Don't ask what it tastes like, I'm not sure I want to know.
0wn3d! - Not much of a hack, really, but it's an image edit that may come in rather handy. Everyone else had one of these, it seemed like...
Breaking News - ...Is this in bad taste? I can't tell. But I can't be the only person who thought this upon seeing the images out of NY after the power outage...
To Wan Fu... - Uh... I think this one speaks for itself. (However, I just may write the fic to go with it.)
Public Service Announcement - My favorite graphics edit ever, inspired by fanfiction.net.
Your Cheating Blade... - This is why you shouldn't let me near scans of the Suikoden novel illustrations.
FF7 for the Atari 2600 - The most famous stupid graphic I ever did. This was the result of a troll who informed the inhabitants of a certain MB that FF7's good graphics were brainwashing us. So I suggested he play this other version...
Makosoft Shindows95 - When the inevitable "Microsoft = Shinra" comparisons arose, I figured this would make a good startup screen for my computer.
Bill Gates' secret identity - Following the above joke to the logical conclusion...
Kill the Monkey! - We got tired of those monkey ad banners, so I decided to do something about it. Apparently the company caught on, because soon after, we started seeing "Punch the monkey!"
Pita Red XIII - Long story, but some boarders held "pitafests", in which we played stoner characters. Somehow we ended up with Bugenhagen and Red XIII being hippie pot smokers who would listen to Pink Floyd while watching the planetarium shows... and Red needed a userpic.
Darth Michael Flatley - Everyone started changing their nicks to "Darth [handle], Dark Lord of the [whatever]" when Episode 1 came out. I figured we needed the Dark Lord of the Dance too.
Dost Thou Desire the Pickle? - ...We have lots of fun with video game villains. You'll see later. This time, it was Xenogears' Grahf who got the treatment. "My breath is the divine fist! Blossom, o fallen cucumber..."
What does the Hamburglar have in his bag? - Terra-ist got this free kids' coloring thing, and decided to scan it in and have everyone else put things in Hamburglar's bag! I don't know why I did this, in particular.
Pokéwing! - Yes, everyone has done Zero Wing jokes now - but we were doing them a couple years before the song and video were made!
Vegeta vs. Cats - See above. :P
Warning about your PS2 - When the PS2 was released in Japan, it had a bunch of "warning!" graphics in the manual, several of which were incomprehensible. The only things I added to this one were the oddish, the arrow from the oddish, and the text. The staryu was already there.
The Chosen One - Based on a quote from Alucard: "He burned down my hometown, killed Aeris, and is now tring to destroy the planet. I'll never forgive....the Hamburgler." I've been told the katakana is the best part of this.
Barbecue - Fun with mixing and matching FF villain dialogue with the wrong villains. I think. ...I'm just not going to try to figure this one out.
Artimecia - Speaking of screwing with FF villains... well, "Ultimecia" could have been romanized in a slightly different way. Also see this version.
Big Muffins - ...This one I don't remember the point of at all. Which makes it even funnier.
Too Sexy - Xenogears' Franz is too sexy for his "seme" shirt. Uh, it's a long story which I don't really remember, aside from it involving #fret finding dolphinsex.org late one night...
VS yaoi evidence! - I suspect this had something to do with the idea Walks-the-Umbra and I had about rewriting this scene in Vagrant Story, so that Callo's power activated just a little earlier... The fun continues here!
Sydney's Special Attack - More fun with video game villains/Vagrant Story. And come on, we all loved his tummy, didn't we?
The Passing of... - We in #fret discovered Oolong's page at some point, and proceeded to get silly. Vagrant Story ending spoilers in this one.
Shinigami... with syrup. - Another Oolong-inspired hack. We did a ton of them that night... Those are some big pancakes.
Have you never been mellow? - Shake it, Snake and Janet. But not too hard - you'll lose your new hats.
They Might Be Pancakes - Yep, more fun with the pancakes. My favorite, actually.
Switcheroo - A meaningful photomontage displaying the reversal of traditional roles given to pancakes and syrup in modern society.
Happy Halloween! - A disgusting news story and a disgusting hentai doujinshi page merge into something that is not only disgusting, but very stupid. Warning - explicit pumpkin-ai content!

Another crazy injoke, involving former GIA staffer Nich Maragos' hat. (The official LiveJournal community can be found here.) Lots of fun to be had.

Toasty! - That Nich! He shows up everywhere!
Haatmadesa! - I opened this treasure chest in FFX and look what I found! :O
Caution! - What's the patch on that hat say? Oh my!

One day in #fret, Rahul decided to edit Sydney Losstarot's head onto photos of various #fretters. In #fret, this sort of thing is not unusual, and a couple of us joined in. However, after Jay got into the act with a rather unflattering edit... I knew where my attention must lie.

Jaydin - Actually, this isn't unflattering. (Hmm, Hardin looks good in yellow...)
Jayshua - Well, it worked well, given the original...
Jaymantha and Guildenben - Wow, Samantha looks hot in a button-down shirt. However, Romeo doesn't look so great in a tank top.