Itoshi yo PLAYGIRL -- I love it when they label people with names, because i think we all know how poor I am at that.
Te wo Tsunai Deikou -- it's the part where they hold hands where i die. Also the part where they are ADORABLE OMG. Is Kota their lead singer? He's full of win.
Angel Come To Me -- Kota with some ridiculous Engrish, and then there is rapping and Jackson 5 singing. JAPAN.
BAD*NICE -- HOLY GOD, SHOON. Is there a HQ version of this somewhere? Is there one that's more than a minute?!
Daite Senorita -- Hikaru, ILU. Also, when they are doing the middle bit, there's a moment of pure keysmash when they all flail their arms at once. you'll know it when you see it.
You hafta be careful to get more recent lives though, because Y3 has been around since 2001 when they were like ten, and also has had multiple member changes since. This group is Kota, Hikaru, Taiyo, and Shoon.
*watches BAD*NICE on loop*
ETA: SHOON IMITATES JIN. Y3 covering Signal. so. much. flail. SO MUCH.