A friend brought over 3 lbs of mussels last week, and I remembered a recent recipe from bon appétit, which sounded good, so I made it:
Spaghetti with Mussels and White Beans. Turned out really good; though I had more mussels than it called for, that never hurt a recipe like that! I may have increased the pepper flakes a little, too.

May be too similar to what you just made, but I wanted to share this.
Here's another I have made for years, with a little heat in it:
Spicy Mussels or Clams Thai Style
1 cup(s) dry white wine; OR 3/4 c vermouth
1/2 tb fish sauce
1/2 tb soy sauce
2 tb cilantro (fresh); coarsely chopped
1 stalk lemongrass; julienned
1-2 superchiles or serranos, thinly sliced
1 large shallot; thinly sliced
1 large scallion; thinly sliced
1 clove(s) garlic; thinly sliced
1 1/2 lbs mussels; cleaned
Combine all ingredients in a 3-4 qt sauté pan and bring to a simmer. Cover and simmer 3 min., shaking a few times, and remove any mussels that have opened to serving dishes. Cover and cook 4 min. longer, and discard any unopened mussels, and distribute the good ones to 3-4 soup bowls. Ladle the broth evenly over the mussels and serve with french bread or rolls, to soak up the liquid.
Option: Clams may be subtituted or used half and half with the mussels.