If you liked Fated to Love You, then you might like The Greatest Love. I'm pretty sure Dokko Jin & Lee Gun are related somehow. LOL
Heard it Through the Grapevine - I've put this one on hold, but the male lead is a handsome kid who is kind of timid and dorky. I don't know if he stays that way throughout the drama, but you might want to check it out and see.
A Gentleman's Dignity - male lead probably isn't as over the top crazy like the guys in FtLY, TGL and Master's Sun, but he comes with his own brand of oddness, imo.
Heart to Heart
Oh My Ghost
In Kill Me, Heal Me the male lead suffers from split personality disorder and a few of his personalities are bat shit crazy (in a good way). lol
Secret Garden also had a slightly odd, primadona type male lead.