Restaurant recommendations for Manzanillo
The long term "best" restaurant is La Tuscana. There is also now La Pergola. For seafood I prefer Bigotes and not on the beach Vaqueros for steak. And of course there is always Las Hadas which has a couple of good (expensive) restaurants.
Here's a good reference although I'm not sure how well it's maintained and how many of these have survived the recession and hurricane.