S3 or Evo or Wait

My contract on Sprint is due for an update. I have never had a smartphone, so I want to make sure I make the right decision. Therefore, I am asking you guys for help on wether I should chose the S3, the Evo, or wait to see what Google does with nexus. Here are some pros and cons:

S3: Pros; super fast, nice screen, true blacks and bluish whites, nice saturation, jelly bean has been leacked for carriers, $100 Cons; plastic build, S4 processor while the s4 pro is out

Evo: Pros; super fast, nice screen, true whites and deep blacks, nice build Cons; S4 while S4 pro is out, still not updated to jelly bean, $200

Lg Nexus: Pros: should be super fast, nice screen, true whites S4 pro, first updates Cons; not as good build quality as expected

So what do you think I should do?