I would have to vote for Zelda over Okami. In particular, Twilight Princess I suppose since it was simiar in nature because of the wolf aspect. I really wanted to like Okami, but after about 5 hours into the Wii version, I realized the whole time I wish I were just playing Twilight Princess again. Some things I didn't like about the game were:
Fuzzy Graphics -- yes, the art style's nice, but everything seemed blurry to me. Edges weren't clean, and colours ran together. Maybe this is because I was playing it on a 46" TV, but after playing for awhile, it felt like my eyes were crossing trying to get the fuzzy lines into focus. I thought at first it would clear up when I got out of that heavenly plain, but alas no. I know it's supposed to represent a Japanese painting, but it really just felt like they were fuzzy from upconversion. I thought the game would be more crisp / cel shaded from small online graphics, but the final product is just too hazy.
Poor Wii Controls -- Sure Twilight Princess was mainly waggle based, but I never fought with the waggling to swipe my sword. Taking 2 attempts at almost each paint brush stroke was annoying at best to me, and more "complex" strokes (the bomb, for instance, which shouldn't be considered complex) didn't register at all. When I slowed down to make a better bomb shape, I often timed out the process because I took too long to make a circle the game liked enough. Maybe it was forgivable when the Wii version came out, but playing it for the first time in December of 2010 it felt like a poor first try to capitalize on the system's motion features. Maybe I was just spoiled by the tight controls of pointer based games like Mario Galaxy, or Metroid Prime, and stepping back a few years felt clunky.
The Chattering Noises -- If anyone found Midna's dialogue to be annoying, I defy them to enjoy Okami's. Zelda's got a nice balance of soothing text tones and when appropriate, quick character noises. The chattering noises each character in Okami for every bit of dialogue grates on the nerves over time. The first few times it's cute, but given the dialogue heavy nature of the game it got to really bother me. Which brings me to my next point...
Too Dialogue Heavy -- I know both Zelda and Okami are based around the same NPC-talking concept, and I'm all up for a reading game, but I found Okami's characters to be too long winded. Rambling on and on about things that either didn't seem important, or were supposed to be funny. When I'm being taught the basics of the game, it shouldn't feel like each little tutorial dialogue takes a minute. There were times where I found my self saying "Just let me play the game", which is not a good thing to experience. This was especially bad in the game's roughly 20 minute opening. I had 30 minutes to spare, so I started the game, figuring I would get into it a bit and save and be done. My whole first sit down was dialogue, and no character control. Zelda may have dialogue, but it seems more concise. NPCs don't rattle on about nothing for much longer than they have to.
The Characters -- Honestly, I just didn't care about them. Maybe it was the lack of facial features, or what have you, but I just didn't feel like interacting with NPCs that much. There were one or two I found more interesting than others, but the incidental ones didn't capture me. Yes, I've grown to love Zelda's main cast, but even in TP while playing for the first time I wanted to know and feel for the new characters without having any preconcieved notion of who they were. Rusl alone captured me in TP from his first lines of dialogue. Issun made me want to get through the game faster so I wouldn't have to deal with him / her / it anymore.
I'm probably sounding harsh here, especially for someone who only made it so far in the game before putting it down, but in all honesty, I've never stopped playing a game before completing it in my life before. I've been playing video games since 1985, so that really says something in my own mind about how I feel about Okami. I think the series would have to really refine the little things before I equated it to the likes of Zelda I'm afraid.