Honestly, I prefer Terraria. They're both good games, I just like Terraria more.
Terraria is pretty much 2D minecraft. Not saying it's a bad game, I just don't see how anyone thinks it's better. Minecraft simply has more options on what to do and where to go. Of course, Minecraft isn't as focused on fighting as Terraria is so if you like fighting more than exploring/building I suppose Terraria is more attractive.