Sassy girl and stoic guy

Bride of the Century
Murphy's Law of Love
My Amazing Boyfriend
Noble, My Love
Waking Love Up
It's Okay, That's Love

Hmm, I'll attempt to try:

You Who Came From the Stars - I feel like these characters fit those descriptions pretty perfectly.

All of the Reply series: (warning they have spoilers if you watch out of order, so watch: 1997, 1994, and then 1988)

Bong Soon - a Cyborg in Love: (a web drama that recently aired--I don't know if she is sassy enough, but she is definitely different, both are definitely self-sacrificing though).

I had to look up what a stoic guy was .. never heard it before! but i can imagine it is a posher word for boring loool

Can't think of anything of hand though but i loved hong nan and seung jae. Still ROTFL at his acting during the p*rn scene lololololololol

@oppalover87 you can't describe seung jae as boring xD, let's call it "silent, cool and enduring" type (with a bit of puppy love going on)? my favourite kind of a guy in dramaland.

@Iwyn, I was recommended Ugly Alert several times now and frankly I am super curious, but the thing is I really dislike "flashback to their childhood" trope that so many kdrama seems to like to employ and Ugly Alert not only does that it goes even further back and into "when their parents met" flashback territory. I don't think I'll be able to survive this much flashback. Do you know perhaps when the actual timeline starts? Maybe i'll be able to watch it if I skip forward.

@ViolinGal, Cyborg in Love was interesting, not what I'm looking for but the dynamic was definitely nice, I liked it.

@werwiewowas95, oh yes Ms. Temper definitely fits the sassy and badass type I'm looking for, Nam Jung Gi doesn't fall into "silent, cool and enduring" category, but you know what I find interesting in this series is the gender stereotype reversal, because in your typical romcom it's the other way around.

Umm..Ojakgyo Brothers?  Format may not be what you're looking for though. :)

Female starts out a little bratty, but it's written in such a way that she's a sympathetic character.  I don't think it's much of a spoiler to say that she matures over the drama.  She has a backbone and stands up for herself, but may not be precisely the "sassy" type.  Male is pretty much the very definition of stoic.  And together they were pretty perfect.

You'll have to wade through the other three couples and the family shenanigans too, and that may be a good or bad thing depending on what you're looking for. 

If you liked Reply 1988, the next best would be Reply 1997. Try it after sometime though cause you'll keep thinking of 1988 if you watch it now. :D

Orange Days (set in university) is also great..it's a little older so it would fit the feel of the Reply series. The female's strong-minded and the guy's the enduring, nice guy type.

How To Meet a Perfect Neighbor, the stoic guy comes on in the 2nd episode.

It's more of a slice of life drama, very underrated and has some very funny lines.