I'd have to say that my favorite March MC is the Demonbow. Back when I joined in '05, I didn't really "get" Gaia. I didn't play the market, I didn't play the games, and I barely hung out. But I always loved the avatars and the creativity that came with making them. I fell in love with the pixel items and the charm of our chibi avatars. My first ever Tektek dream avatar had a Demonbow in it, and I've adored the item ever since. XD There's something about it that really makes me love it; probably because it gives the avatar such neat wings. I had that item plastered to my avatar for about a year. It, the Chain of Command, and the ORLY bag were what made my avi who he was back then.
Clearly, that's not the case nowadays, but I still hold a huge measure of fondness for that there Demonbow. It was a prized possession of mine...though it's one I haven't put on in awhile. I'ma go dust that baby off, methinks. <3