You can't compare WoW to RS. Yes they are both MMO's but MMO's don't all fall into the same category. Someone made a point of RS being browser based, nail on the head. Browser based games are in a genre of their own. If you compare the two of course WoW will win. WoW is 5 years younger than runescape, that in itself make them incomparable for so many reasons. RS was and is a F2P game (w/ p2p features), which puts it into a whole other category.
Come on, all the WoW users that continue these types of arguments can't be that stupid or have that small a penis to put up this big an commotion over little old Runescape ( or other games for that matter.)
I know people that still MUD to this day, and have a blast when they do. Even PnP people. I see 90% WoW users complaining of boredom while they grind the same boss the 500th time trying to get that 1 piece LOLZ. It's all subjective.
I'm an ex-wow player, played until recently, liked it when I played it. I have tried Runescape and I thought it was great for what it was.
Runescape wins by default, it's been around longer, been through more changes, and is still going strong.
Games successes aren't measured by the amount of money they make, some may disagree. They are measured by how content the devs are with what they created, how content the user base is, and if the game still exists in any form.