Most difficult levels in existence?

[M11k4]

Of the ones I've solved, these took the longest to just figure out:

CCLP3 #144 (YCTaOFNT)

CCLP3 #147 (Avalanche)

pi^2.dat #10 (avalanche)

pi^2.dat #14 (avalanche II)

pi^2.dat #15 (modulo fourteen)

I also spent quite some time on these, though not quite as much as the ones above:

CCLP3 #137 (Vulcan)

CCLP3 #143 (Same Game)

pi.dat #12 (the wrong parity)

computer.dat #10 (different game)

minustwo.dat #4 (D)

KeyboardWielder.dat #121 (In the Line of Fire)

I haven't solved these, but suspect these should also be mentioned:

pi-rejects.dat #8 (bugs)

pi^2.dat #13 (crash and burn)

minusone.dat #9

minustwo.dat #8 (H)

There's only a couple in there that are challenging to execute once you know what to do. I also remember taking forever to solve Checkerboard I long ago without a map :-)

-Miika