Leon is by far my favorite RE character. He has been since the original PSX game came out. I love his character model and love that he's one of the few male characters whose defining qualities (at least initially) are naïveté, idealism, inexperience, and earnestness. It's a refreshing contrast self-assured machismo of Chris or the world-weary ruggedness of Barry, and certainly something I very much identified with as an awkward teenager. He's almost the male version of Rebecca, who was always my favorite woman in the RE mythos. Claire, on the other hand, has always been sort of a enigma to me. In the original version, I somehow assumed she was older (at least in her early twenties) and imagined her as a bit of a tomboy who was using all the stuff Chris had taught her to survive in these absurd circumstances. The newer version seems to ratchet up the Claire as college girl stuff, endowing her with a more youthful appearance and tweaking her dialogue to match that persona. Unfortunately, that makes the simultaneous amping up of her bad ass, take on all comers approach to gigantic mutated creatures and zombie hordes seem really incongruous and pandering. Maybe the newer version is what they always intended her to be and I only liked the old Claire more because she was less defined, but the person in the newer game feels less than believable and pretty incoherent as a character.
All that being said, while I'm not entirely finished with Claire's story in the new game, I prefer it to Leon's so far. I liked Claire's version of the story more in the original version as well, so I'm not surprised. I was never a huge fan of the Ada stuff in Leon's scenario and find her to be an extraordinarily grating character. On the other hand, I really like the character of Chief Irons and think he's one of the best aspects of the entire game, narrative wise. In terms of character broadening sidekicks, I like Sherry's engagement of Claire's dormant maternal qualities more than Ada's toying with Leon's fluttery heart. I also enjoy that, from a mere practicality standpoint, Claire seems to have about twice as much expendable ammo and three times as many healing items as Leon.
So, love the character of Leon. He'll always be my favorite. But the Claire story is more enjoyable.