I would say either GURPS or Shadowrun. Gurps is a tighter system, but more complex than I like. On the other hand, it is more adaptable to the particular type of tech you want. Tech can be interpreted a whole lot of different ways, and at a whole lot of tech "levels," so you have to keep in mind what you want from that.
I would imagine, like others have mentioned, that a superhero game of any kind would work well, but they aren't my bag, so I can't really make a suggestion comparing any of them to the two I mentioned.