Ok so there's 16 gotten so far. I've got the solution so I've checked them. The fish in the bowl is Phish, not Aqua, and Tatu isn't the two people making out. The correct answer is more about what they're doing than who they are. Clue: they used to wear weird make-up!!
If ye want anymore clues, let me know!!
Gorillaz (well, the gorillas in the picture)
Scissor Sisters( the two pink scissors)
Matchbox 20( the 20 on the ground made out of matchboxes)
Guns and roses (by the guns in the roses)
50 Cent (by the silver half dollar...)
Smashing pumpkins (by the smashed pumpkins)
The Eagles (by the birds)
Beach Boys (by the two surfer guys)
Phish (orange fish in the bowl), its not Aqua
Eminem (open bag of M N M'S on the floor)
Blur (man in pink shirt is blurred)
Garbage (there is a load of garbage coming out of that black bin)
The Rolling Stones (stones rolling down road)
Red hot chilli peppers (by the red hot chilli peppers)
Lemonheads (lemons with faces)
Blind Melon (the watermelon with glasses)