In the original it was Leon. I liked Ada more than Sherry, not to mention I prefer his guns, he didn't have the Grenade Launcher, but I loved the Magnum and Shotgun. The bit where you are with Ada is also pretty cool, while with Clarie you have to walk slowly because of Sherry.
In the Remake, I think the story is better with Claire, Irons is more interesting to meet than Kendo, and while I loved Ada in the original, I find her annoying here, the bit before the Alligator always drags on because of plot exposition, and Claire doesn't have that problem. Aside from that, on the gameplay front I find both scenarios identical. In the end, I think Claire is better because of the plot.