Oh yes I feel you, I really find a lot of kdrama's male leads super annoying.
-Reply 1988 (all the male leads are lovable. There is also a good comparison between the 'jerk' male lead and the really likable, kind and soft-spoken male lead (both are male leads...no second). I highly recommend Reply 1988, especially if you dislike annoying arrogant male leads...you'll see the start contrast and it'd be really satisfying. I mean, there cannot be a more crazily likable male lead in the history of k-dramas. I think this drama would be perfect!
-Kill Me Heal Me (funny how this one has more than one male leads too...of the same person. One of them is the type you'd hate/love because of his arrogance and all that, but the other ones are really, really likable!)
-I Love Lee Tae Ri (the male lead is a 14-year-old boy who turned into a 20-something man overnight. So naturally he is really sweet and adorable, and not the arrogant, annoying, and horrible male leads I know you are talking about.)
Since I probably hate unlikable male leads more than you do, trust me on the other dramas where I find the male leads likable:
I Remember You, Ugly Alert.
(^that's pretty much it, lol. Sometimes the leads are OK but not particularly likable in all aspects, so.)