I am thinking just to access generic stuff through the normal net for the casual crowd they have augmented reality. Glasses, cybernetic implants/eye, or even AR contacts. This would be honestly more real and futuristic, I really cannot see anybody carrying around something bulky like a phone anymore. They are all wearing it and it is all wireless access, so people can send files/records digitally to each other through the net. However, I do NOT want to be able to hack boringly this way where it is all text files/screen interaction. Someone in the real world would have to get the information the old fashioned way, get passwords/access codes and do it slowly.
Real Hacking should happen in cyberspace, I think the wireframe/reskinned city idea is the best. Everybody and everything that has access to the net (data points located and moving around in their equivalent location on the world) would appear as wireframe Ghosts of the real world objects? of their real world parts with information above their ghost forms showing information of their system (AR glasses/cybergear/security..etc) and maybe show their difficulty hacking rank. If you want to hack into it then you "touch" the asset you want to hack which would create a "dungeon" level you are teleported too depending the rank of the system. This could easily be created through procedurally programming, so the devs would not have to create each individual room. A rank 1 room would be a smallish room with a single security bot, while a rank 5 would be a massive building with lots of patrolling security programs and defense measures.
What would be cool is that when you get access to the system, you could do all sorts of things. If AR is common, then you could access their video feed and watch whatever the person is looking at, everybody could be a spy camera. If they have brain implants, you could brain hack their memories(rewriting/erasing) or even upload a virus that turns them into kamikaze killers, or even possess the NPC directly. You could disable their cybergear. If you have access to a vehicle, you could look at the cameras, the previous records, you could take control of it from cyberspace and do anything you want.
Cyberspace should be filled with defense programs patrolling, although the patrols focus on corporate locations and not that much in average locations. The character and other hackers should have unusual avatars(including the main character), nobody is going to give their real identities in cyberspace. There also should be hacker hangouts (own personal dungeon areas for hackers that are hidden).
I think hacking programs should be like magic. As you gain programs you gain powers. You can summon a defense program, you can shoot a virus that could destroy, or take over a app, you can teleport to a new location, you could fly around cyberspace, etc.
I would also say that once you been to a place, you can instantly teleport there any time, and if you tag something and get its IP addgress, you can always find it again (like a moving asset).