I've been dissapointed with various cameras. Like mentioned above, I bought an LC-A+, didn't like the way it focused at all. I'm trying to get into my Leica but it's not as exciting as I thought it would be. And it weighs like 5 pounds so it's not exactly easy riding around on my bike and shooting. I suppose if I had a $1200 super sharp lens, it might impress me more. I have a cool looking Canon 28mm lens mounted on my M4-P, but I don't think it is the sharpest lens. I really have a hard time getting into 35mm in general. I keep thinking about getting a GR21.
There are various "toy" or vintage cameras that have been pretty boring to me. Most look cool on the outside but produce pretty much the exact same image...soft and low contrast, nothing that particularly stands out.
Since I shoot tons of Polaroid, I'd have to say I was pretty dissapointed with the couple different auto folders I've owned, like the 100, 105 and 150. I guess after using the 190 and 195 for so long, I think the output from the auto folders is pretty crappy and they seem to make muddy shots. I even think the hard plastic cameras, like the Colorpack III, are better at exposing.
Most TLRs I have tried have been less than interesting. Couldn't get into the Yashicas. I didn't like my Lubitel. I've had a Rolleicord and a Rolleiflex. Both were okay but I still sold them.
I find I need fewer cameras the longer I shoot. I used to buy all kinds of cameras to try them out. My problem is I don't like to own things I don't use, so to buy something and just leave it out on a shelf for decoration doesn't much appeal to me anymore (except for maybe my Fujipets). Now I just like to find the cameras I really like to shoot with and keep using them...