Peanut butter and almond butter are fairly similar nutritionally. However, there are some differences, and it looks like almond butter may be a little better for you.
Peanut butter is a good source of protein and monounsaturated fatty acids, and it has some magnesium, potassium, selenium and a few B vitamins. One tablespoon of peanut butter has 94 calories, 4 grams protein, and 8 grams of total fat.
Almond butter has a bit more fat than peanut butter, but that includes more monounsaturated fat and about half the amount of saturated fat. Almond butter also has more fiber, and fewer carbohydrates so it has about the same number of calories as peanut butter.
Almond butter has more minerals than peanut butter, with the exception of selenium, plus peanut butter contains more B vitamins. Both almond butter and peanut butter contain phytosterols, which are the plant versions of animal cholesterol; however, unlike dietary cholesterol, phytosterols may help to reduce elevated cholesterol levels in humans.
Both peanut butter and almond butter can be used as sources of protein and healthy fats, just be sure to look at the ingredients labels to look for any added sugars or other ingredients you may not desire. It's also important to note that people who have peanut allergies are at a higher risk for tree nut allergies, so almond butter may not be a good substitute.
United States Department of Agriculture National Nutrient Database for Standard Reference, Release 23. "Peanut butter, smooth style, with salt." and "Nuts, almond butter, smooth style, with salt." Accessed March 17, 2011. http://www.nal.usda.gov/fnic/foodcomp/search/.