Fire.
An Immelman is one of my favorite inversions, and fire has TWO.
I also think it was such a great and original idea putting an airtime hill on an inverted coaster.
Fire also lasts a few seconds longer. While Ice is about to hit the brake run, fire is going through it's last inversion. It's not significant, but I noticed this while riding Ice.
I love Zero G Rolls, but I don't think they are nearly as good on an inverted coaster as they are on a coaster that is above the track (standard or floorless).
Cobra rolls kinda bore me, and I don't like the "snap" at the top, but they do look awesome.
An interesting comment though, I read what Jakemeister said on the first page of this thread and I just though it was funny that I have the exact opposite opinion. I think that Fire is better overall, but that Ice gives a better front row ride. I always go for back row of fire. Fire for me is about intensity, Ice seems to give a better ride that will make you feel like you're flying (near miss with the castle wall, the view while going around the overbank turn)
It's also quite funny that in the poll, the Fire Dragon is blue and the Ice Dragon is red.