Well for me the first is definitely Eitan's Star. Then there's the Geranium which I still am trying to solve but to no avail. My third will be the 3x3x3 Mix Up Plus. I know it's probably not that hard, but I still find it really annoying for some strange reason, probably because I keep forgetting the set-up moves.
I don't want to think what the 4x4x4 Mix Up Plus is like for me.
Those three are for me personally. I still don't have enough hard puzzles in my collection, so I unfortunately cannot really give another two that I've actually tried out.
However looking from what is up right now on hknowstore, I think the bandaging on Justin's Pocket Cube looks hard. I guess that's where getting the Bandage Kit from CubeTwist is probably a good idea. Also, I've seen the solving required for the Dayan Gem VII and it does look like a satisfying challenge. Eventually I'll get these two.
So there's my five. Not that great as I'm still pretty bad at solving in general.
Challenging enough for me personally at least.
Tony Fisher wrote:
I've finished stickering my Camouflage Cube:
But anyone can see it a mile away with those colours!