The biggest thing for TV shows is finding characters you root for, who you want to see succeed- whether they're actually good people or not (for instance, Tony Soprano, Walter White are two bad guys who were such great characters, you rooted for them nonetheless).
Entourage suffered from this as, really, Vince, E, Turtle and Drama kind of sucked. You did have Ari, who was awesome.
Ballers- who do I root for here? Corddry's weaselly character? The Rock's wooden character who's rich enough to wear ridiculous suits and drive awesome cars, but we're supposed to want to see him succeed? Why? And ALL of the football players so far are nothing but dumb pieces of ish. Why should I care that Ricky makes it? The guy is a moron and an a-hole. The big defensive lineman is even worse- a really stupid human being.