Rock Puppy is my favorite. I mean I have major love for Bammi and Hammi but Rock Puppy is awesome. He has a pose where he's flying at you to attack you with his love. He is just so adorable though he isn't quite house trained. He leaves some stinky surprises.
Lunar Scythe is my choice for being my favorite. Not only this item was awesome looking, but had may different equip functions. Go from the God of Death with one blade to having it have a duel blade to strike fear in the most fearsome enemies. If that didn't suit my taste, then I would equip 2 of these bad boys as scythes and it gives me feel of power of fear. If I feel like being a weapons master, then I would equip 2 of these on the back gives the look of a huge double sided Scythe that could rip apart anything in my way or show that I'm a force to be feared. Too boot, this item doesn't look cheap nor tacky which is a major plus.
I wanted to put a different answer than everyone, but I'm gonna have to say my favorite April MC would be the Oculus Magica. It's just so awesome. Everyone loved it, everyone wanted it, and it went with almost everything. The Oculus Magica was the first eye "item" on Gaia, and it created a path to items with eyes.