probably the one who sent me 3 mails within 10 minutes regarding 3 different positions, and all were addressed to someone else (Hello, Mr. Completely Different Name), so i replied telling him that's not me, and gave him the info to fix it in their db. he apologized profusely and said he fixed the error.

Next day I got two mails for another two positions, with the same incorrect name.

Or the one with whom I had half an hour phone "interview" for a specific position, they couldn't answer even the most basic technical question about the project, but invited me to an in-person interview and said my questions will be answered there, the phone interview was just to make sure they don't send completely offtopic people to the interview with the client (so far acceptable).

On the in-person interview, it was partially a repetition of the phone one, but okay, lady from the company is talking to me first time in her life. We get to the part where I can ask my questions, so I ask those basics about the project again, and her answer is:
"Oh, i don't know, i'm not a technical person, you'd have to ask that to the technical person from the company, I'm an hr person from the recruiting company."

"Wait... so... not only was this whole meeting a waste of my time, but you also lied about what it is, when you scheduled it with me on the end of the phone interview?"

"Well... it wasn't a waste of time, we like to meet the candidates in person before we forward them to actual interviews in the company, to make sure that they're not completely offtopic."

"... and how exactly do you think you'd be able to evaluate that, since you're not at all a technical person and know nothing about the project??"

" Well, i talk to programmers a lot, so i've picked up quite a bit of the terms."

...