The brutality of it is keeping me watching, that and hoping that king kid get's his face butchered and then gets bummed to death.
Season 6 and 4 are the best I'd say. Season 1 has a huge amount of characters to introduce and doesn't have as much action as the others, so I found it a bit of a slog the first time I watched it too, and was also wondering what the hype was about. Season 2 starts off slower but gets a lot more fast paced towards the end, the last 2 episodes of that season are awesome. When I re-watched Season 1 I actually enjoyed it a lot more than I did first time around, there's a lot of stuff hinted in there that you don't pick up on first time, but becomes clear after you've seen the other seasons. But yeah, persevere with it, you'll get in to it eventually.
I'm on series 4. Trying to catch up before it starts, reckon might just about manage if it I do a couple episodes a night.