As usual, let's call the pics A, B and C. A and B are bands. C is a group of people who are more of remixers (they remix high-profile songs) despite having their own recording career. (Sorry about size of pic C, that's the biggest I could find)

Connect.

Toughie there I guess (since there was hardly anything to start guesswork with)

A. The Thompson Twins
B. Tin Tin
C. Tin Tin Out

All names were inspired by characters in Tintin comics.

Nikhil identified B. Good work.