I'm not even saying this just because it's easy to pirate, I'm saying it because the officially licensed products, at least the ones in English, are worse than fansubs you can find online. Unless maybe you're a dubfag, in which case, get the fuck out.
Also, watching it out of order? Why? Just start at the first episode of Dragon Ball and watch everything in release order. Many would agree that the best parts of the series are before Z, anyway. Or just read the manga. Personally, I actually enjoy the filler and movies, despite frequent but relatively minor contradictions with the manga material. Also, I'm not sure what the general feeling on this is, but I actually think Kai is worse than Z, due to the filler actually being good sometimes. Especially in the first arc. If I want a version without any filler, I'll just read the manga.
A few years ago I marathoned the entire anime series in order, and went out of my way to find and include any animated material I could find that was outside the series. Not just movies and specials, but PSAs, OVAs, video game tie-ins, animated sections from weird Japanese exclusive consoles. A lot of it was pretty fun, and mostly fits okay into the timeline, if you adjust a bit and don't necessarily put everything in release date order with the series. For example, a lot of movies and stuff happen between when Trunks arrives and when the Androids arrive. It doesn't fit perfectly, but it sort of works. The filler and other stuff does reference other elements of filler and other stuff sometimes, which is kind of neat.
GT is underrated. It drops off hard in the second half when they beat the first really major bad guy, but I'd say it's worth watching, and immediately after Z, as that's when it was intended to be watched.
One problem I have with Super is that it begins with very long adaptations of Battle of Gods and Resurrection F, but the adaptations aren't as good. So just watch the movies, right? Well no, because stuff that is only in the anime adaptation is referenced later. Also there is the manga, which also covers the same stories, and continues covering the same stories as the anime all the way through, but they're different. It's not like the original manga and anime, where they're the same story but one has filler. They're the same basic idea but told differently. The plot is generally better in the manga, more well thought out, but it's rushed because it's trying to keep up with the anime. And sometimes it feels like you're intended to be consuming all three versions of the story, because it almost feels like one version will gloss over things that are only fully explained in another version. Like for example, the manga skips Resurrection F, because there was already a manga of it before Super started, but the manga stops partway through the story and tells you to watch the movie. I think I recall better examples from later, but frankly the rest of Super isn't very memorable either.
Right now the only one going is the manga, and it's good, because it doesn't feel rushed to keep up with the anime, and it seems like the guy writing it is given more control, so he can actually put thought into the story and do cooler stuff. Also, at least the manga didn't bother trying to adapt the Broly movie, so there's only one version of that to worry about. Unless the anime comes back and stretches that out to 15 episodes as well. I suppose if it gives the manga a few more months to build up good material, I wouldn't mind.