These are all pretty good logos - better than what I could design. Have you ever considered adding an actual line to the designs or did you think that was too cliched or obvious?
I guess I like the bottom left one the best - I think that's the one that looks the most professional. I like the twisted looking logo and the gradients used. My second favourite is the top right one because it has fun attractive colours and it looks professional. The top right one I think has some awesome wit to it in the R, but looks a little old fashioned and the bottom right one strikes me as a little childish due to the colours and the crayon-like texture to the shadows. It also strikes me as stereotypically feminine due to the colours used, which may not work for marketing and media services.
I hope you found this critique helpful and I haven't trod on your toes in any way.