There's one out there for everyone who has more than one razor. It's the one that you really really want to work for your face. You've heard so much about it, everyone raves about it, but dangit - it just won't give you a good shave! Maybe it's that 1912, or the Aristocrat... either way, it's out there.
Mine is the slant-bar. I have a vintage Coles slant that just won't give me a consistently good shave, even after months of tying.
What I'd like to know is, what's yours? What's the razor that just won't work but that you keep trying?