KE economy is fantastic.
I've only taken KE, OZ, and UA to ICN but hands down KE was the best and OZ was a close second. UA, on the other hand, was horrible; the seat was OK (UA 744 ICN-SFO in E+) but the meal service was severely lacking and, of course, no seatback IFE.
KE is phenomenal. Like a poster above, I usually take KE 93/94 IAD-ICN route. It varies from a 772 or 773. Both are fantastic. Here's the lowdown:
Seat: 34 inches of leg room. Everytime I go on a KE flight and then I get on a domestic DL flight, I wonder, what the heck is up with our domestic seats. However, KE's domestic seats (flights within Korea) have very little legroom.
Boarding the plane: Upon boarding, you can pick some newspapers to take; there is usually Korean, English, Chinese, and Japanese selections. At your seat, you get a nice little bottle of Jeju water (think Fiji water but from Jeju Island in Korea). Last year, they started giving amenity kits as well which includes slippers and a toothbrush in a nice little blue pouch. (I think I'm forgetting something).
IFE: Lots of newly released movies on-demand. Touch-screen works well. There are two different types of IFE... I think they call it I and II. I is older but they've been making improvements to the software so much so that now I prefer I to II because of the map features are more interactive than the II system. II is usually on 773s and I is on 772s. There are also power plugs 2 for every 3 seats. If you have a laptop, between that and the seat back AVOD, the flight is pretty nice.
Food: OK, I will have to admit that I am biased since I am also Korean-American. I love KE's in-flight food. There are usually 2 meals from the US to ICN. I always order the Korean one so I will describe those (I think once I ordered the chicken and ended up with a Western meal and looked on with jealousy and envy at those with Korean meals because it looked so much tastier to me). Also, I have never seen kimchi served (probably because non-Koreans generally don't like the smell... well even Koreans don't like too much kimchi smell)
Meal 1 (the larger one): Bibimbap usually comes out as the first meal. There is bibimbap, some type of soup (either seaweed or a fermented bean soup), and pickled cucumbers. I've also had Haagen-Daz ice cream served once in a while (ICN-HKG and back).
Or, there can be a larger Korean dish. It'll usually be a chicken or a beef (Korean style) or a few banchan (side dishes you get at a Korean restaurant) put into a dish, some rice, pickled cucumbers, some fresh sliced carrots and cucumbers that you can dip into a red pepper paste sauce, and tofu with soy sauce-based sauce. Soup is also served.
Meal 2 is usually smaller. It could be Bibimbap or Bibim-gooksu which is the noodle version of bibimbap. It'll also have a small soup and some type of fruit (last time I had a fresh clementine). If it's not either of those, then it'll be a smaller version of the Korean meal I described above.
Snack: They usually come out with snacks. Either pizza in a small box or a triangle kimbap (rice and some type of meat or fish wrapped in lavar in the shape of a triangle; it's actually Japanese) thing. Both are good although I do like the pizza more...
All alcoholic drinks are free and coffee and tea are usually served after the meal.
Lavatory: As a whole, I am really impressed. I once went to use the lavatory and saw a KE flight attendant cleaning the bathroom. She then let me in... once I was finished, she was waiting outside and went right back in to clean the bathroom. It's the little things I notice, i.e. toilet paper is folded into a triangle, all water is wiped, mirror is crystal clear. Also, the flight attendant had a can of air freshener. Hopefully not because of me...
Overall service: All of the flight attendants I've encountered speak fluent English; from what my friends in Korea tell me, candidates must achieve some level of English fluency to become a flight attendant. I rarely speak English to them but I've heard them speak English with other passengers. They sometimes could have a very thick accent. On the whole, they are very professional and I've seen them go out of their way to help out fellow passengers. I once ordered a scotch, which they forgot about, so then I asked another flight attendant. As she brought mine, the other flight attendant I originally asked came and profusely apologized to which I said, nah it's fine, don't worry about it.
I also love these stickers they have that you can stick to your seat that lets the flight attendants know to wake you up for duty free shopping, meals, or to not disturb you. Again, one of the small things that makes me smile.
I always go out of my way to get a KE flight now. OZ is comparable to KE but they still need to work on the smaller stuff.
Hope my post wasn't too long. I can't wait for my next KE flight!