The Strongest solutions
Problem: You can insert everything but numbers, and you can't change anything. I'm pretty sure you can only insert on the left side of the equal-symbol.
0 0 0 = 6
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

The Strongest solutions:
  (0!+0!+0!)!=6
(1!+1!+1!)!=6
2+2+2=6
3*3-3=6
√(4*4) +√4 = 6
5+5/5=6
6+6-6=6
7 - 7/7 = 6
8-sqrt(sqrt(8+8)=6
sqrt(9)*sqrt(9)-sqrt(9)=6

URL: http://able2know.org/topic/132706-1
of all the solutions, I think the solutions for 0s and 1s are the strongest, how had the solver thought out the use of factorial, it is absolutely one of the strongest solutions in the history about the number riddle.