The last one, but it needs simplifying. You could the man's head and little hands, but either way I'd enlarge the graphic in the circle. Then lose the outer rectangle and sort out the massive leading on the type.
Apart from the second one down, they're all just collections of bits in a web-button style.
No.2 has the makings of an actual logo.
Best tip is always design in 2 colours and keep it flat. Once the logo has been worked on and signed off, then it can be embellished with these very common place 'button' effects.
I liked the 2nd one (of the 1st lot) best. More of a logo. Should always start with designing in mono first then go to colour. Agree with Curtis - play around with the logo.
These last ones seem less original.
The CMYK thing is done to death with anything to do with printing. I would avoid that if you would like some originality. The latest designs are looking simpler, and the simplest designs usually work best