I've played many, many WCIII mods (I think my "downloaded" folder had six hundred maps in it before I had to separate them by type, because it took so long to load when hosting!). I can also honestly say, DotA is not among my favorites.
The game is almost all about items... items over skill. You sit there, wait for a mob to be at 2 health, then make sure you get the kill so you get money, and thus items to kill things faster.
You should try Enfos (Enfo's Team Survival). It's a great game where mobs come from the top and walk down, around you point, then in it. You can only leak a max of 100 mobs. You have offensive spells to use on your enemies (yes, you can even one-shot some really bad players on the other team) or on the mobs you're attacking. It is also very loosely item-based, at least for casters. All you do after maxing your inventory with some items and potions is buy tomes, and there are so many mobs you can't really "steal" kills very well, especially at the end.
There are so many better games than DotA out there.. you should really just jump into tons of random maps you've never heard before.