What makes Girl's Generation so special 또는 better yet so 인기 then another group in Korea?

In an attempt to answer your question- I don't think it's any *one* thing that makes them popular. They have some really great songs (that is, of course, something that people could argue against, but even my younger brother who does NOT understand why I listen to 케이팝 admits that he likes some of their songs)

Another factor is that there are so many of them. Some people don't like that. But I think that it makes them different. They really stand out because of it, especially when they are all dancing in sync.

Third point is their personalities. They laugh, makes silly jokes, and behave sort of like 'the girls down the street'. Meaning? They give off a feeling that they're like your 프렌즈 또는 sisters. That really made me like them. In their video Gee (my first introduction to them) they weren't dressed in super-revealing outfits while doing suggestive dancing. They were wearing jeans and doing a fun dance. It was a very pleasant change from what I've seen.

Speaking of concepts, their concept keeps changing. I see that as a great thing. The only example I can think of that *might* not get me into trouble is Taylor Swift. I'm not an anti, but her songs have very similar sounds. Though I liked the first few, I got bored of them over time. With Girls' Generation, if 당신 don't like their current sound, 당신 can find other styles that they've done. My mood in 음악 is constantly changing, so it's nice to be able to go from listening to Merry Go Round and Baby Baby to Wake Up 또는 Oscar.

All in all, that's at least part of why they are special to me. I don't think it's a contest, so I'm not even going to argue that any group is 'better' than another group. I'm just saying that this is why *I* like them.

Now I'd like to know something, why are 당신 here? ^__^? Don't take offense, I'm honestly curious. Do *you* like Girls' Generation? If 당신 are, what's your answer to your own question? ;)

It's because SNSD have good pitch for each song . They have a good voice && also if 팬 사랑 them then that mean it's because of their songs . && btw , they did got " plastic surgery " tbh , but it's not their fault that their so pretty && stuff . Maybe how the way they dress .

Wanna Know why they are so Special? well SNSD have long proved their ability as live performers of 음악 and dance, But what really drove them to the 상단, 맨 위로 was their multi-dimensional talents and charming personalities. These girls always radiate a cheerful and friendly vibe, and behind the scenes they’re a very decent, respectful, humble, hard working and professional group of entertainers.
another reason is their individual charms..and i mean everyone would agree, snsd are very fun, friendly and enthusiastic girls. that’s the trick. people 사랑 when girls being all dorky and spontaneous. not like ‘im so pretty, i need to be reserved’. even though they are soo incredibly beautiful, snsd are different. their always like ‘bwuahahaha’ when they laugh not the average ‘hihi’ korean pretty girls would do. each member had their own strength to make snsd’s 더 많이 popular.is there any other korean girl group outhere like SNSD?

Make no mistake, their success is the furthest thing away from luck. It’s a perfect storm of how great people, great material, great production, and great execution came together...

It's a mix of everything. The girls are actually pretty gorgeous without make up, ant they were cute too, before plastics.
The thing is, SNSD is legendary because they were the first girl group to be that 인기 not only in Korea, but also worldwide. SNSD is a mix of everything: foreigners, good dancers, very good singers - Taeyeon beeing one of the best female 케이팝 vocalists, and again, gorgeous girls that fit in the Korean beauty standards.
Talent: Most 케이팝 groups are majorly made of cute people (Monsta X, Twice) that have no to poor good singers, 또는 cute people and average everything (Blackpink, BTS). It's hard to find a group that feels as good as SNSD in every role. I only know EXO, EXID and Sistar that fills all the roles like SNSD in aspects like that.
SM entertainment: No need to say more. Veterans in making average look like gods. This entire company is filled with smart people, from very good composers to smart businessman. Their insanely repetitive and no-rest promotions over SNSD in Korea and 일본 just make it easy to remember the songs and the girls' faces/voices. Just think: how can 당신 ever forget Tiffany's Mr.Mr high note, 또는 Jessica's "hey boy, do 당신 believe this situation", 또는 even Taeyeon's I when 당신 hear it ALL THE TIME EVERYWHERE.
Yoona: Most female 인기 idol, i think 의해 now she is not the MOST popular, but still the most powerfull. SNSD's face of the group acts like a magnet to new 팬 and it's still today, the Goddess of female idol standards. For 10 years, Yoona's been making SNSD look sexy af.
Hard work and past: Most of the girls were already famous before debut. Yoona was very 인기 and Taeyeon had released several recordings before 2007 SNSD's debut.
International success: Tiffany and Jessica were from America - news to koreans at that time. Sunny was Lee Soo Man's niece, Hyo was a good dancer already. Sooyoung did some 연기 and Seo and Yuri were new faces(i'm not sure bout them, actually). With The Boys huge success and international debut, Girls, alongside 2NE1 - I Am The Best - and BIGBANG's Fantastic Baby at the time, brought a huge international highlight over Kpop. With that, new kpoppers came, and naturally did, sometime somehow, known SNSD. New sones come, and when I Got a Boy massive humongous success wins Youtube's Video Of The Year, the 원, 동그라미 repeats.
That beeing said, of course 당신 can have good voices, like Hyolin 또는 even Chen. 당신 can have pretty faces like Nayeon 또는 Jin. Good dancers like Lisa 또는 Taemin. Good rappers like Vernon 또는 CL. But it's very hard to have fantastic singers with beautiful voice tones, the most 인기 female idol, a huge agency, international recognition and good dancers.
Ps: i wasn't shading no group. It's honestly an innocent review.

I think that it's how they act. Their personalities and how the girls interact with each other make them interesting and fun to watch on variety shows, concerts and interviews. Each member has something that make her different from the others. Also their achievements make them different from other groups. They are 케이팝 girl group pioneers in a sense.