Absolutely. Now, the question is who is my favourite pony.
Sure, sure, I have a "list" I go by, but those only concern the canon characters.
Were my OC, Drakk, real and in mortal danger... I would definitely heroically, gloriously and humbly sacrifice my life so that he, my essential child in all but blood and reality, would live on.
... Darn, I have tons of other OCs too. Well, thankfully, most of them aren't ponies.
Anyhow, were I to choose from my favourite canon characters... Well, I'd honestly give my life for just about all of them. Which one would I save with the least hesitance, though? Celestia, Harbinger of the Sun, Ruler of Equestria, Sunbutt. Her, I would save without an ounce of hesitance. Well, considering I'm not staring in disbelief that she's real, anyway