This is my first review, so hopefully it isn't too bad. But if you just want it short: I absolutely love this product, and it is by far one of the most superior that I've tried.
------ Background:
I am an NC45 in MAC Studio Fix powder and #170 in MUFE HD (and I will likely never return to either of their foundations), and I use MISSHA M Perfect Cover BB Cream in #27, Honey Beige. ---
Now, most would ask how that's even possible since CLEARLY #27 does not match NC45, and is at the most made for NC35/42. Simple: after applying the bb cream over my face, I use a very pigmented powder that matches/is close to my natural skintone. And...that's it. It's the best thing I've ever used in my life. HG. HG. HG. I am in love, even if it's only been for two months.
------ Umm...:
"Why not use #31, Golden Beige? It's darker." - The #31 has more red/pink undertones, whereas I have mostly yellow/golden undertones. It would look very strange with my skin color.
------ Coverage: Light to full; buildable; up to you.
If you're a girl who has some dark spots, or other pigmented scarring, or spots in general, from acne or anything else, that you're still trying to get rid of and heal - don't be so quick to believe those who say that this product is absolutely, without a doubt sheer/light coverage. At least it isn't the way I'm able to use it? Since from my perspective, it covers amazingly well! However, there are various perspectives on what constitutes "sheer" anyway, but I almost feel like "covers well" is an understatement, as this covers everything I need it to. Yet, it doesn't do this in an unnatural way. I have no need for concealer anymore. No supplementary creams, liquids, nothing. This really is a primer-foundation-concealer-moisturizer all in one. ^__^ The time it takes for me to do my makeup has been cut in half, which is a great thing if you're a college girl like me, or just want a simple, non-heavy look on some days. I can't even put into words how glad I am to have finally found a product that does what it promises (most of us have experienced the truth behind the lies of MU companies).
------Benefits...
that I've noticed - my skin texture has improved, it's brightened my face, lightened some of the dark spots I have, I don't feel it on my face, lasts 10+ hours without needing a touch-up (does depend on weather and application though), and while I do not have acne-prone skin, I have noticed fewer, smaller breakouts :] Even though you don't notice it, can't forget about that awesome SPF 42! Also, one pump goes a very long way. For problem areas, maybe only 2 to 2.5 pumps. 3 pumps on bad days. I have so much product left even after two months of (mostly) daily use.
------ Basically...
I've been searching for makeup that I could finally have on my skin, without feeling like I was going "one step forward and two steps backward" every day. You know? The thick foundations and concealers that feel like they're heavy and suffocating your skin all of the time, with absolutely no benefit to your skin other than a little SPF and full coverage. I'm trying to achieve that kind of "flawless", no-makeup skin (not a look - the real deal), and I honestly feel like MISSHA M's BB cream is going to help me get there sooner. I would recommend this product to everyone, the only cons being the cost and limited colors, though it's still a better color selection than the other true (true, as in, none of that drugstore faux BB-cream, tinted moisturizer junk) BB cream brands like Skin79 and Holika Holika. But for my HG, my love, I will definitely spare the $27 (I bought it on ebay, with fast and free shipping, but sometimes you can find it much cheaper). It has helped me so much, and I hope it does the same for others!

This is for the Perfect Cover in shade 23, natural beige. So far, so good! I'm an Asian and my shade range is about a NC 20, give or take (slightly darker in the summer). Shade 23 works beautifully for me. It initially goes on sort of grey/white, but then oxidizes to blend in with your skin. I know some people don't care for the scent but it didn't bother me since it was mild (smells like slightly perfumed baby powder). The texture is very lightweight and goes on smoothly, unlike other BB creams I've tried. It's also nice that this comes with a pump to be more hygenic, and also comes with an expiration date on the box. The only reasons I would hesitate to recommend this if you are medium skinned, and for anyone looking for more moisture. I wouldn't say that it's particularly hydrating so anyone looking for that better look elsewhere. I also respectfully disagree with reviewers who recommend this for NC 27-30 (which I've read elsewhere). I actually think it would look ashy on anyone who is even slightly darker than the NC 20 range. I think it's a great option for relatively light skinned women with combination skin.

This is by far the best BB cream I have ever purchased. I've tried "Western" BB creams such as the ones from Garnier and Maybelline before, but they were all disappointing. This is the real thing. I've ordered it on eBay and it was shipped from South Korea.

First, it matches my skin tone perfectly. I ordered no. 13, which is a tad bit too pale for my fair skin, but it makes me look like a pale porcelain doll, which I love. Unlike Western "BB creams", which tend to come in a veeeery limited range of shades and often look too orange, this one is very neutral, it has no orange undertones and comes in a wide variety of shades, 5, I believe.

The coverage is superb. It covers literally everything, I've had foundations that provided a much worse coverage than this. Any redness, pores or dark circles are gone, it's amazing.

The consistency is thick and creamy; a small pump is enough for the entire face. It blends easily and becomes one with the skin, it's virtually invisible that I am wearing makeup.

Another thing I very much like is the sunscreen, SPF 42, which is very high and perfect for my sensitive skin. As for the smell, although some have complained that it is very strong and matronly, I for one, cannot sense any. It has a very discreet scent and very neutral. Overall, I am very satisfied.

Cons: It does contain some mineral oils and parabens, so I do hope it won't break me out in the long term.

I like this product, not "wow" effect but i like this. Not love but like.
¨Good coverage, cover eye circles and even freckles too.

I am sincerely disappointed. I wanted to try Missha BB cream after reafing all of these great reviews. I really wanted to love it. Fist day of using it: Felt soooo goodddd.It did gave me the natural coverage I wanted. My skin looked smooth and it was glowing. Second and third day of usage: A huge pimple appear on my left cheek, then another one on my right cheek, then another one and another one... It's a nightmare, Don't use this product if you have oily or acne prone skin. It may fit to the dry /normal skin but not for the unlucky oily/combination/acne prone skin. :(

I got the #21 as a new customer free gift. It is too pale for my NC30/35 skin, but hey, I didn't pay for it. I use a darker loose powder on top to get it to look more natural, and it works. I was concerned that it would break me out because it contains beeswax and fragrance; I have been using it for over a week and my skin has been surprisingly good. One complain is that the texture is too balmy, I have to be rubbing my skin way to hard to blend it properly. Now I put a sunscreen around my eyes before this BB cream to help with the skin pulling problem. It isn't a bad product, but I probably won't buy it again, mostly because I don't want to get violent with my skin to blend, and it has more coverage than I need for an everyday look.

LOVE this product! Blends amazingly, looks natural, leaves a dewy finish, long lasting, and smells great. Doesn't break me out. Love love love!

Shades Comparison Reference:
#13 Milky Beige - NC10
#21 Light Beige - NC20
#23 Natural Beige - NC20, NC25*, NC30
#27 Honey Beige - NC30, NC35

(All based on other people's reviews)
* most people using #23 state they have NC25 skin tone but there have been a few that caution #23 users to be below the color range of NC27-30. YMMV :/

Love it. Pretty good coverage, does not make me breakout, and fairly long lasting. Only problem is it might not be mositurizing enough for people with dry skin; I can only use it during warmer months since Canadian winter is quite cold and leave my skin dry.

This is a good product since its not too thick, doesn't have overpowering smell, and is cheap if you know where to buy.
It's sad that the other comment seem to have bought a fake Missha since the way they describe it fits the fake ones.
BEWARE OF FAKES. GO TO A TRUSTED SELLER.
signs that the product is fake: smell is overpowering, easily broken bottle, have slight defect or have poor quality packaging, more oily that when you put it in a tissue, the oil will easily spread. (don't put something like this on your face! be aware. :) )