If you did a modern campaign set in the 80s what would be your take on it and which system would you use?
Yeah, that's what I would do. Top Secret to Top Secret! There is sauerkraut in my lederhosen.
Yeah, I'd second Top Secret, though I might use the more recent NWO ruleset, which is super-elegant and so easy to learn.
I've been on a Miami Vice kick lately, too - they're all on STARZ, so I could get behind that. I also might want to do something inspired by Roger Moore-era Bond and Schwarzenegger action movies - which pretty much describes how I ran Top Secret at the time.
Alternately, if I wanted to do something that inserted more hi-tech/fantastical elements into the 80s, I'd use Fantasy AGE + Titansgrave or Shadowrun Anarchy.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.