Cheddar and Pepper Jack cheese are uncommonly good together, in my opinion. For a nice cheese sauce with a kick, the chopped jalapenos are a great booster and match perfectly with the flavor profile. Feel free to experiment with other types of cheeses. Try some gruyere cheese, white cheddar or smoked gouda. These are just a few ideas, the options are almost endless. Try your favorite cheese, but make sure it's a melty cheese.