My favorite is probably sparse jungle, not full jungle. Then dark forest is second place. I like the vibrant shade of green given to leaves/grass by the jungle/sparse jungle biome. Did you know villagers can have a jungle themed skin if you spawn their egg in a jungle biome?
same here. i like jungle cuz it look pretty and flourish you can visit at 12021 at smp6, and u will saw jungle mansion made by me
Overall, it's gotta be the snowy taiga. I don't think there is a prettier biome out there. However, I also love the ocean biomes, they aren't really practical for exploration. I'm a huge ocean nerd, so they are essential to me. Honorable mentions go to the plains biome (nice memories of hunting Momentus and Marlix back in the day) and the mushroom fields biome (the location of my first EMC friends' outpost we founded; plus, it's quirky). Nether-wise, I'm going to offer an unpopular opinion and say that the Soul Sand Valley is the best. I love that eerie look. Close second goes to the equally unpopular Basalt Deltas; I just love blackstone.
The snowy taiga cause I like the look of the dark trees with the snow. Plus foxes are a really nice bonus.
Mesa until it was updated to be more severe badlands. Held a hard mode LAN game on one once. Food was the real issue there, after falling. There would be one or 2 trees you could get to and oak gives a decent number of saplings so there was that. Desert is nice, mobs are easy to see coming. Hate creepers. Dark oak forest is so deadly with creepers around every tree. But this one is okay if you walk tree top to tree tops. Ditto for jungles... I seem to have a theme. I do like traveling rivers overall. Usually connect a couple biomes.