what is the best art piece you have ever gotten of an oc?You have no idea what you're asking me to do. 0_0 I have so many amazing pieces of art that I've gotten over time of my OCs that I don't think I could even just a few, let alone just one that stands above all the others. X3
But...I'm going to go with this piece:

by Peace&Colby of my beans Amanda Lynn and Toothless. ♥
Okay, it's not one character, it's two. But they're mates and I fawn over this piece so much, this and several other pieces. But trust me, there are a lot more art pieces that were the best I'd gotten of my OC. X3
Are you automatically turned off to a character if it isn't a common species? (like, canine/feline)Nope! Unique species are something I'm fond of. My automatic turn off? The cost. If the character is being sold for dA point. Off. (I don't make any points on my dA account, I've never even opened up commissions on there). If the character is being sold for USD. Off. I have to draw art of one of the person's other characters...maybe off. Generally I get turned down anyway because my art "isn't what they're looking for."
Do you ever get 're-attached' to characters once people start offering for them, even if you haven't used them in a while?Yes. x3 I've totally had this happen. X3
What makes you most attached to a character? The amount of time you've had it? The amount of time you've SPENT on it? It's design? Rarity?Hard to say actually as it varies. It tends to be sentimental, the amount of time I spent on it, the ability to relate to the character, length of time I've owned it, the inspiration of creativity that they spark in me. X3