I really do enjoy The Golden Army, but my vote has to go to Blade II, because that movie is just awesome IMO, although the first Blade is probably my favorite overall. To me its honestly kind of sad that those movies don't get the same recognition these days as some of Del Toro's more prestige films.
Now, don't get me wrong I liked Pan's Labyrinth and The Shape of Water, but its not like those are my favorites of his or the only ones worth talking about.