I do think HBO is still the best pay-TV channel, but their originals are not as popular as they were a decade ago. However, their movie lineup is great. I wish HBO would repeat more of their newer movies like Starz.
As for Showtime, their movies are not good (expect for the "Twilight and Weinstein movies"). Their originals are getting better and their advertisements/promos are simple and professional. Still, HBO has better movies and original content than Showtime.
As for Starz, better movies than Showtime but they can't compete their movies to HBO. However, I like the way their repeat their newer movies because there are a lot of channels out there and people have busier lives. What Starz and Encore needs to do is the maintain the Disney and Sony contracts and add another major studio and they can be OK with their newer movie supply in the next few years. Also, they need to add older/recurrent movies that have not aired on their network before. For example, add some 20th Century Fox movies from 1998 to 2003.
As for Starz' originals, not as good as HBO and Showtime. It will take some time for them!