Attention, Love! - they live together as teenagers, during college as well and once the male protagonist gets drunk and she stays with him in the same bed. Nothing happens but they sleep together.
Beautiful Gong Shim- She gets drunk and sneaks into his apartment ( she's his landlord) and they wake up together. Happens several times and is hilarious.
Blood- She gets in bed with him, his bed is is cold, like he keeps it freezing cold to be able to sleep since he is a vampire. She wears winter clothes to sleep with him, very cute.
Bromance- they go camping together, they also share a bed during a cruise trip, male lead gets hugsy while sleeping.
Cinderella and the four Knights- She gets in bed with him when he is in the hospital, cute conversation.
Devil Beside You- A little bit more on the hotter side of bed sharing.
Eternal Love, aka Ten Miles of Peach Blossoms- Multiple bed sharing situations, going from cute to hot. YeHua is one of my favorite male leads, if you like unwavering, never ending love, totally devoted male character. Plus, he is hot too.
Full House/ Thai version- They sleep together during a trip after a very cute and hilarious fight for the bed.
Hi my Sweetheart- Another drunk sleep together, hilarious morning after situation.
Hwarang- He is injured and she gets in bed with him to warm him, he is asleep though and wakes up to being hugged by two of the other male leads.
Introverted Boss- Various sweet moments of bed sharing and talking. She scares him by being a little pervy but is nothing really dirty.
All the versions of Itazura na kiss involve some sleeping together or bed sharing or laying down.
Love in the Moonlight- Very cute, innocent bed scene in which the lay next to each other and see into their eyes. I think it happens more than once.
Marriage, not Dating- Has both cute and sexy bed sharing.
Mars- Sleeping together scenes, they move together so you have a couple of cute waking up scenes and a hot going to bed scene.
Oh my Venus- Sexy scenes in bed but also very cute ones.
I actually know many more that I may add later. Hope this list helps.