I'm not a fussy sort of chap, I've liked something about most of the knives I've ever obtained; even some really cheap and technically quite poor ones.
There are still some dire ones though:
The first knife I bought myself was truly one of the worst bits of metal I've come across-I've had bits off a computer case take a better edge etc. It was one of those hollow-handled "survival" knives with all the tat in the handle and sheath, including such delights as a bent wire that was supposed to make a slingshot, a compass that only pointed in one direction...or rather didn't. In the end I managed, by hand, to bend the blade in a complete circle.
After that I bought a set of tiny cheapo throwing knives, which were pretty bad, but heat treated and wrapped they've actually come up ok; so after a long time of regret I'm actually ok with having got them now.
Cheap Chinese SAK copies...gone through a few of those; to be fair the most recent one wasn't actually bad (not like a real Vic, but takes a decent edge and has solid enough tools for using-and I won't really care if I lose it either

).
The only one I still have but reget ever buying is a Gil Hibben Claw, I can't think of anything good to say about it at all. Maybe someday I'll do something with it that'll make me change my mind, but I doubt it.