Dota for me.
Although I like the Warcraft 3 version a lot better, the new one just feels "off".
//Top Reasons for loving it in no particular order.\\
(1) Roles for carry/tank/support/jungler doesn't feel as trinity to me than in LoL. We can go all Int based and still kick their ass.
(2) I remember most games ending up to be 4v5 within 10 minutes and we, on the 4 man team would still royally kick the other team's ass.
(3) When a ally player left, you could take their items.
(4) Killing creeps is more money satisfying, including denying creeps and towers and ally heroes.
(5) Ganks are a lot easier and more prone to happen, including team fights.
(6) The ability to juke a entire team without using a single ability is extremely satisfying. But tangos and teleport/boots are still good.
(7) Gold penalty for dieing.
(8) All heroes are available to you.
(9) Couriers
(10) Pit Lord, Jakiro and KotL!