When I get bored, I surf Flickr for beautiful cosplay pictures so you don't have to do it. Here's a great photograph by Joe Lim from Comic-Con of a guy dressed up as one of the characters from Kingdom Hearts. There are several things that make this an example of cosplay at its best. First, the hair: this cosplayer spent a lot of time creating the ultimate anime hair, making it stick up at crazy angles and turning it a ferociously artificial yellow.
As for the costume itself, not only is it pleasingly complete -- full of matching shiny bits -- but it looks kind of hot. Most importantly, the sword and key look great. You can't really call yourself a true cosplayer without some serious accessories. In this case, the main accessory is a sword (if you look up Kingdom Hearts on Flickr, you'll see some great cosplay swordfights). But it could be wings or a little dragon perched on the shoulder (oh how I love seeing a pretty Pernie girl with a little gold dragon on her shoulder).
Finally, the true test of a good cosplay display: did it make me want to figure out what the hell Kingdom Hearts is so that I could appreciate the costume in context? Hell, yes. Now I'm the last dork in the world to know this is a Playstation game that combines Disney characters with Final Fantasy characters for a lot of swordplay and exploration. And cuteness!
Video Game Character Cosplay Group on Flickr [via Flickr]