I love that this thread exists; everyone here is pretty awesome. I've been sewing for...seven years, now, maybe? Anyway, these are a few of the things I'm proud of, but finished before I joined the RPF and so haven't had an excuse to post.
This is a coat from Fire Emblem I made for a friend (modeled here by a completely different friend who just happened to be around when I finished it)


I made the cloak and jacket for the Dream in this Sandman group (and had to hand-dye a gradient into the flames)

I would have twice as many costumes if I could stop making things for friends who pay me mostly in pizza...but I do have a few. My latest is Wiccan, from the Young Avengers comic. First time making something out of spandex; it was an adventure. When I was wore this to Anime Detour, the guy selling leatherwork in the dealer's room asked "Where do you get something like that?" and when I said I made it, he got all incredulous and said "
You made that? Not your mother, or your sister, or your girlfriend?" Nah, man, I make my girlfriend's costumes. She's going to be Batgirl, and it's going to be awesome.
I also embroidered the entire plot of an old Scottish ballad onto the back of a doublet, for some reason. And then I embroidered a million (approximately) silver keys onto a surcoat. I may be the Abhorsen someday...if I can make/acquire a set of matching silver bells of different sizes. But I'm a seamster, not a bellmaker, and for now I'm stumped...

The surcoat ended up the style it is because I miiiight have started it after playing Assassin's Creed for three days straight. Maybe.