League has a different balance philosophy. DOTA makes damn near every champ a 'carry' while league has more champions that cant do this and play a more team oriented role. I prefer League's method but to each his own and neither are more or less balanced than the other.
@canteu: I'm not asking if they're different, no, because I know they are. My original question was "Is there someone as different from the rest as Meepo or Invoker?", with added examples.
Karthus, Ryze, Ahri, Victor, Le'blanc. Those are vastly different champions and all fill the same role of 'mage.' While there is no Invoker type champion, that type wouldn't work for league.
On side note, while I think DOTA is geared more towards pro play, League is much more successful on the competitive scene. I don't think DOTA can hide behind 'its a beta' anymore, League has the bigger fan base and thus the bigger pro scene.
This is actually completely false. I would say that there are less heroes with carry potential in Dota than there is in League of Legends. The very existence of something like Ability Power or spells that scale off of your right click damage makes it so that there are more heroes with the capability to carry. In Dota 2 you will never make Crystal Maiden's spells do more damage, and her auto-attack and Strength and Agility are so godawful it is nigh-impossible to deal significant damage.
As for your examples of heroes that are different but fill the role of "mage." That kind of archetypal role is completely devoid in Dota. Heroes are categorized by farm priority rather than any sort of capability they have. Whether the hero has stuns, or burst damage, or the ability to farm quickly is something you consider in your lineup. You don't take Wisp because Wisp is a support, you take Wisp because you want the unique aspect that Wisp brings to the game. Dota has more heroes that change the dynamic of the way the game is played. League of Legends has more heroes, on average, that just sort of have different ways they do the same role as heroes that are similar.
I will say though I am sure League of Legends is more successful competitively. It is easier to get into and follow, and Riot throws tons and tons of money at the competitive scene. Valve supports the competition with their single tournament and through the game, so they just have a different approach. For example, now you can buy an item in the in-game store that the money goes to the prize pot for the big tournament of the year, the International. A great way for players to support the pro scene.