My four nominations go to... badlands. It's mountainous, so you get more materials. There's also a lot of terracotta and extra gold. However, I only find the regular badlands worth dealing with, at least for surface mining terracotta. The hoodoos in eroded badlands and dirt and oak forests in wooded badlands are annoying to deal with; there's also the chance of lush caves being a further nuisance under wooded badlands. Last but not least, the deep dark can spawn in low-erosion areas, which can be dangerous. desert. It's great for sand and sandstone, which means great for glass and TNT too. It's flat, so no jagged terrain like you'd find in windswept hills, windswept forests and windswept savannas. It's also moderately eroded, so there's not likely to be a deep dark in the deepslate layer. However, deserts in more humid regions can have lush caves underground, which can be a hassle. Falling sand can be frustrating too unless you're deep underground or quarrying. stony peaks. It's mountainous, so you get more materials. There's also a lot of emerald ore and sometimes calcite. However, there's also the chance of lush caves being a nuisance if it's humid; this is a bigger issue if there are jungles around instead of forests, plains and savannas, though (although forests can still spawn on the plateau-level mountain slopes above the jungle sometimes). The scenic views of the surrounding jungles and savannas, chance of getting calcite strips on the mountaintops and no snow or packed ice to contend with makes stony peaks, at least for me, far superior to frozen or jagged peaks. However, the deep dark can spawn in low-erosion areas, which can be dangerous. swamp (both temperate and mangrove). It's great for clay or mud, and there may be some sand and extra gravel too. It's flat, so no jagged terrain like you'd find in windswept hills, windswept forests and windswept savannas. It's also highly eroded, so there's not likely to be a deep dark in the deepslate layer. However, swamps of either type in more humid regions can have lush caves underground, which can be a hassle. Water can also be frustrating unless you have sponges and wall off your quarry, or mine underground only.
I was about to say dripstone caves because of all the copper, but then I saw your selections and realized the best biome is just the one that contains the resources you need for a current building project.
I do agree that dripstone caves is a good one, too! I was thinking mostly of gold, terracotta, emeralds, safety from the warden and no snow/ice/thin soil to contend with. Still, dripstone caves is also great! If I had to do a top five, I'd be torn between dripstone caves, jagged peaks (which have snow but no ice) and one of the two badlands variants as my fifth nomination.
