On the 24 servers I like Holiday, because there are at least 3 good routes, although the water is an issue.
On the 48 servers, I like SG Kingdom and Castle Dracula. On Castle Dracula I have a solid chest route, and the enchant table makes it fun to try and get XP. On SG kingdom, despite lag from the vines, I enjoy this map because my route is solid, and not very many people know what they are doing.