Playing in a tournament using the 6.59 Dota Map? It pays to know the meta game. Here are the Hero Tiers. Know the game and win. Here they are in no particular order.
Top Tier
These are heroes that are banned or picked most games.
Lock, Puck, Zeus, Lich, Spectre
Naix, QoP, PoTM, Omniknight, Earthshaker
CM, Tidehunter, KOTL, NA, Chen
Brood, Pirate, Visage
Middle Tier
These are heroes that are frequently picked if they fit a lineup.
Sand King, Lina, Meepo, Tinker, Luna
Pit Lord, SF, Lion, Axe, DK
Enchantress, Krob, Rexxar, Tinker, Storm Spirit
Centaur, Chaos Knight, Necrolyte, Stealth Assassin
Surprise Heroes
These are situational heroes that are used in competitive play given a proper lineup.
Dazzle, Invoker, Lancer, Juggernaut, Witch Doctor
Gondar, Pudge, Panda, Medusa, Slardar
Enigma, Sven, Skel King, Viper, Vengeful Spirit
Venomancer, Phantom Assassin, Jakiro, Drow, Pugna
Furion, Bane Elemental, Huskar, Abbadon