This is like the presidental election, everything sucks,, but which one sucks less? Vagex is horrible, you need so many credits which wouldnt get counted as youtube views, but it helps with SEO ranking. Using subs/favourites/comments/likes on vagex is a joke.
U2BViews has a terrible program, checks for flash too often and is just too slow upon using it, their services however is decent as they can deliver comments and likes to how you wish. But has a terrible audience retention.
EnhanceViews just sucks balls now, get banned in seconds.
SYV is decent, but its all mobile views. If you only care about numbers, then its perfect for you.
Anything else sucks balls to the point of no comparison.