I'll tell you why I like HoN the best. (I actually played LoL, HoN and Dota unlike you who played only 1 game and think it's the best - this is retarded)
1/ Dota: Yes, it's good. I played it for 3 years and I enjoyed it. Still, the graphics are old school, gameplay is slow-paced and w3 engine limits developers' thoughts and ideas. The platform which is dota mainly played on is Garena, which is a big retarded piece of spastic community using hacks and cheats daily and moreover Garena won't do nothing bout it.
2/ HoN: Best graphics out of the three games, gameplay is fast-paced, it is much more dynamic than DotA, and it has got 90% features as Dota does. If you like DotA, you will like HoN, unless you're retarded. I was having the same attitude like retards in this topic such as "DOTA ONLI OTHER GAMEZ ONLI COPY PASTO!!!!! JAJAJAJA", but I was forced by my friend to try HoN, and yes, HoN succeeded. It has many new addons like anti-leave protections, when disconnected u can return back, and many other.
3/ LoL: It's good, but it differs from Dota/Hon a bunch. . There are some skill trees or smth like that, I don't like that. You gain with that adventage over the other players (who just started playing LoL) in the beggining of the match, which is unbalanced. You cant DENY IN LOL < LOL!!!! - wtf? You can't deny? BIG MINUS!!!!!! You deny properly you must have a little skill, in LoL you dont do this - LoL doesn't require skill in one of aspects = big minus. Graphics are walt disney - dislike. One good thing is that it is free.
Conclusion:
If you're pussy, play LoL.
If you want to have some fun + cheats, hacks, play DotA on Garena.
If you want to have serious and good DotA games, play DotA on RGC client.
If you want to challenge real pro players, play HoN.