definitely netrunner or Solo. For a COP, I prefer yhe universe of the french PnP RPG game, COPS
Those that most intrigue me would have to be Rockerboy, Netrunner, Media and Techie. I really hope they nail the classes so that they each make for an entirely unique playthrough...
I really like the idea of playing as a Night City Cop - A Cyberpunk cop was my default role in Face of Mankind...
I choosed the one i want to play first, because i want to test ever class 
This is how I usually roll with RPG games. (No die-rolling puns intended.)
I plan on a play-through with EVERY role, but I'll most likely start with a Solo.
I would really want to try out Media if there is the class in the game. And if we can combine, then Solo Media
Solo, because habit.
Media and Rockerboy and Netrunner and Corporate all next, all at once. I 'm thinking about hiring an actor to play me in real life so I'll have enough time to do this game.
Then Cop Nomad Tech and Fixer.
Those might change depending on what we get. If netrunning isn't supe rcool, then no. Tech might be awesome - Jury rig is one of THE coolest skills ever. Make a device to do what you want for X minutes depending on Special Ability? Yes,please, I'd love to have a rocket launcher that shoots ice cream into my cyber mouth and yodels in Japanese while doing it.
Who wouldn't?
Media and Rockerboy and Netrunner and Corporate all next, all at once. I 'm thinking about hiring an actor to play me in real life so I'll have enough time to do this game.
Then Cop Nomad Tech and Fixer.
Those might change depending on what we get. If netrunning isn't supe rcool, then no. Tech might be awesome - Jury rig is one of THE coolest skills ever. Make a device to do what you want for X minutes depending on Special Ability? Yes,please, I'd love to have a rocket launcher that shoots ice cream into my cyber mouth and yodels in Japanese while doing it.
Who wouldn't?
...I have to say: I never imagined cops would be so popular in the dark future. Ha.
I'm having a hard time imaging how they could make the game suitable for all roles. For example a Cop is going to have vastly different interest and goals than a Rockerboy. It's not like Skyrim where you just have different approaches to solving the same problems. A Cop is about solving crime, while a Rockerboy has little interest in that but would be interested in getting a gig.
Yeah, this is a trick. The PnP has a section on how to get the Team together - the Hook. After all, in most RPGs of the time, all you needed was a bar or inn and an adventure. And loot.
In CP2020, players are more likely to loot each other for their organs than "go on an adventure" together.
Trick is to find a story that drags them all in. Hire them, blackmail them, steal a girl/boyfriend, get a big story on the Street that calls in all the necessary skillsets, that kind of thing.
The Street finds it's own uses for things, to quote some guy.
Solo, with a "score 1 of humanity". Living on the edge of a cyber psychosis. Cyberlimbs, full replacement of skin by a shield layer (like the girl in the video), cybereyes with improved aim, thermal and night vision among other stuffs, nanobots, internal brain's chip for silent communication and the list go on...
It is tempting, but to be honest, I doubt that rockerboy, media, corporate and fixer will be playable.
Most of my Cyberpunk PnP games have been heavily themed, all mercenaries, all cops (although dual roles were allowed), or a band on tour, for example. That's normally the easiest way to keep the group on task, rather than at each others throats.
Not sure how a sandbox game could have quest that would attract the attention of such a diverse range of roles. How would folks react to a game were the roles were restricted. Say Cop only.... Like the trailer, you could certainly fill a sandbox Night City with plenty of quests a cop would be interested in.