As far as I made it Perrin was actually my favorite character. He wasn't Rand "All the Chicks Dig Me" Al'Thor or Mat "Cleverest Dude Evarrrr" Cauthon, which somehow made him more real to me. From what I understand he became much less sympathetic after my stopping point, Book Six-ish, so I admit I'm not seeing the whole picture.
Actually, for what it's worth, that was my take on Perrin too, and he was my favorite character as well. He did wrecked at a bit as a character as the books went on, but I still liked him.
But talk to anyone else in the fan community, it seems, and Perrin is hated for being "boring" and "uninteresting". To be fair, it doesn't help that for a good chunk of several books, his story and the rest of the cast basically don't intersect much, and sometimes not at all.