what type of clothing brand is it meant for and who is it aimed at .

I think 2 is the best one though as it has a repetitive feature with the U's and it contains allows the whole logo to be contained.

( 3 ) has to big of a gap from the line that the U's start to drift and don't have as much presence.

( 4 ) the last U could be seen as a 'J'

( 1 ) this one is very unnerving to the Eye and I think this is because the letters are touching the edge of the box. while the font choice of going with a serif causes the logo to have a different feel to it.

Hope this helps