I highly recommend basically anything from Sally's Baking Addiction. I've never had one of her recipes fail, and they've always come out absolutely delicious to the delight of my family and friends. I also like her site because she actually covers a lot of details about what's important to pay attention to in each recipe, which substitutions work & which don't, qualitative as well as quantitative criteria for each step, and both metric and US customary units for ingredients.

Recent award-winners include her Schwarzwälder Kirschtorte, Seriously Fudgy Brownies, Maple Pecan Tassies, Gingerbread Cookies, Very Peanut Butter Cookies, and multiple cheesecakes based on her classic recipe.

I also recently made Claire Saffitz's chocolate layer cake that was featured in NYT Cooking.