Best and worst steels to sharpen?

Curious what steels you guys found easy to sharpen and which annoyed you to no end.

I would say CTS 204p is my favorite, honestly seems slow to grind even with diamonds, but takes a razor polished edge. Most annoying was s110v, WILL NOT polish, looks like it was ground on the sidewalk with both the factory edge, and after stropping, also takes a very light touch to get razor sharp.