Maybe you'll have to look into variety shows. Let me recommend: Jung Hae In's Travel Log and Real Mate in Cairns, Australia
My Fellow Citizens! - the two main leads are already married, he is just hiding is real occupation from her.
Navillera - No romance at all. A very good drama. There are some semi crazy relatives and other characters, I think.
Tunnel - The story of a man who travels forward in time to capture a serial killer. There is a romance aspect b/w ML and his wife and two of the mains (?) in the current era. Although, when ML finds out that FL (?) is his daughter he gets protective of her. I thought it was more sweet and funny than annoying though.
Healer - does have a guy interested in FL for about two seconds but it isn't really a part of the story and can be overlooked for the MUCH better relationship of two really good actors with amazing chemistry and (continue rave here).
Horimiya - I don't remember a triangle, slow romance, irritating friends/family in this one.
On the opposite end of the spectrum, because I feel like mentioning it, how is Hyde, Jekyll, Me for a love triangle? 1 male with split personality and 1 female that falls for one and ends up with both.