I agree with PinkFloyd, the politics, while somewhat bull, are a major draw-factor for me too. I love all the friendships, fallouts, back-stabbings, and letting all of this define your agenda. It also creates a back story within the sandbox that you can follow back right to the start of eve.
Look at the eve wiki pages for any of the major alliances, and you can be captivated for an hour reading about prior battles, movements, tactics, ceasefires, wins and losses....
And when that alliance has a load of Roleplayers on board, they manage to get the story they are weaving and the result of the battles to tie in with the chronicals and fan fiction. There are a sea of bloggers out there, far to many to read, who blog about every battle and the reason behind every battle.
Then you get videos like this which just make my jaw drop:
http://www.youtube.com/watch?v=XulF-5UU34Y
The story line and the depth of this game are what hold me addicted and captivated every session that I play.
Yes it takes a lot of commitment, some days I commit more time and effort to eve than I do for my job. And yes it takes a lot of resources, but its possible to get anything you can buy from jita into nullsec at a reasonable price if you have a solid industrial and logistical backbone for your corporation.
And if you're sitting in safe spots for two hours you have a rubbish FC and should move on
