What is the funnest virtual world

My Top List.
1. Maplestory.com
--Completely Free if you don't mind not having nexon cash which can buy you amazing clothes, better hair, eyes etc (not essential). Maplestory is a MMORPG (massive multiplayer online roleplaying game). Millions of people log into maplestory everyday. Must have 2 GB available as a download is required.

2. Habbo.com
--Completely Free, if you don't mind not having a cool room and lots of credits (habbo currency). This is just a place you can relax and chat.

3. Runescape.com
--Completely Free, if you don't mind being basic. Like maplestory, not the nexon cash, though.