In Ocarina of Time, I feel very relaxed at Romani's Ranch. I also feel this way at the fishing gorge, but moreso at the ranch. As young Link, I'll go there and throw my boomerang in the air over and over while Malon sings as if these were two farm kids simply playing in the field.
In Majora's Mask, Clock Town is definitely my favorite place to hang. If I had to choose one specific location, I would say the Stock Pot Inn because I always wind up spending a lot of time there, but really, I enjoy the entirety of Clock Town, specifically on the first day. There's something about a peaceful stereotype environment that really gets to me. Children running about, the one cranky guy, hardworkers... sigh.