Whats the difference between HoN, LoL and Dota! xD
HoN is a lot more exciting than LoL a lot more fast paced less flashy abilities (so you have to really pay attention) much more PvP action instead of killing the NPCs known as creeps for money and exp.
LoL is pretty much the opposite in the way described above, but still shares many if not all concepts that are in Multiplayer Online Battle Arena genre games.
Dota is kinda in between
I find it's good to get together with friends and do things, like... movie/series marathons, beach, pool, parties, etc...
Or, just do some gaming and foruming. Try mix it up, if you do all gaming and foruming you'll probably regret it as the time will feel like it's going a lot quicker and by the time it's over it'll feel like you've done nothing with your holidays.