Check out the New52 Action Comics. Grant Morrison's now famous t-shirt and jeans Superman is widely popular among fans and it'll give you a strong sense of the Golden Age social crusader that Superman started out as. Morrison wrote from issue 1 to issue 18, as well as the 0 issue and if you can roll with his weird head-trip story telling its one of the strongest runs Superman has seen in thirty years. Then skip everything until issue 24 or 25 when Greg Pak comes on. His run starts with a stand-alone, t-shirt and jeans era story where Superman tries to stop a major hurricane headed for Gotham. One of the best one-shot issues I've read in ages. And then Pak's run really starts, and it's everything a good Superman comic should be; it's got weird ideas (the Ghost Soldier, Subterrania,) heart, humor, soul, and a Superman who doesnt take any crap but isn't a complete douche. It's got a sweet pulp feel to it as well, which fits the character nicely.
I also suggest Superman and the Legion of Super-Heroes and Legion of Three Worlds. Both by Geoff Johns. The former puts Superman into the 31st century to help the Legion defeat a xenophobic villain who is corrupting Superman's legacy. The latter is a Final Crisis tie-in and puts Superman back in the future trying to defeat Superboy Prime for the last time. It's a little continuity heavy but generally it shouldnt be a problem.