I fund it somewhat hard to decide on this but in the end LotR wind by default, really. D&D is both directly and indirectly spawned from LotR. My favourite pen and paper RPG is actually Icelandic so it would do dreadfully in international polls.

I'd like to see a poll between Eberron, Forgotten Realms, Dragonlance etc.

Boooooooooooooooooo!!! D&D FTW!!!

LotR is very pretty. but also boring and realistic
DnD is full of sex and violence and humour.... and it can be pretty too!

D&D... Forgotten Realms in particular. Though I am fond of my own world, Pylandor

D&D is even to nerdy for me so LOTR.

D&D
because it allows me to make a world of my own

LotR. Tolkien doesnt change the rules every 2 years!

If talking about movies LOTR. If talking about RPGs D&D.

Well, LotR was around first, and is likely the world most fantasy realms today are loosely based on so there should be some measure of homage in any case. Though I have to give it to D&D. Why? Because of things like Forgotten Realms, which have been in development pretty the last thirty years. That's a lot of time and a lot of descriptive fluff to flesh out a world.