Yuri, Yoona, and Tiffany are the WEAKEST members let's be real.
shut the **** up. Tiffany is easily the second best voice of the group after taeyeon. and Yuri... well Hyo and yoona are better in term of dancing, so i don't use Yuri, she also acted weird very often, like when they were performing on live with kelly. Gurl... get yourself together.
Yes most people pass them off because they A.) don't like them B.) there's so many they just assume they all are basic.
But Taeyeon, Jessica, Seohyun, Sunny & Tiffany all have great voices. Actually Yuri & Hyoyeon have decent voices too. Jessica & Seohyun are my favs vocal wise
Taeyeon has one of the most beautiful voices in the industry. Sometimes people just focus on their looks so much that they forget these girls have amazing vocal ability too.
Tiffany's husky and warm voice always gives me chills.
The beauty 
Remember how consistent she is in The Boys' live performances. She's got talent.
Hopefully Soshified subs it quick every week.