How do you know that ole' Bruce Schneier was not covertly paid by the NSA to inject weaknesses in his designs ?
If you take the paranoid stance that NSA is powerful, aims at making encryption systems weak, and may resort to tinkering and bribery to that effect, then claiming that any specific system author is immune and obviously clean from such interference, is pure wishful thinking. For that matter, it would make more sense to believe that the AES itself, i.e. Rijndael, is "unmodified by NSA", for the basic reason that the Rijndael authors are not American, and thus less susceptible to NSA leverage than Bruce Schneier.
Note that I do not claim that Bruce was bought off; Heavens forbid that I accuse without any proof someone whose appearance is so uncannily similar to that of Chuck Norris. But I mean that you are not thinking your own question through. If your enemy can manipulate algorithms to include weaknesses "in plain sight", that hundreds of trained cryptographers miss, then you cannot trust any algorithm, regardless of its purported authors.
Now if you really want raucous gossip, rumour was, at the time of the AES competition, that the NSA candidate was MARS. Cryptographers did not like it, not because of its purported ascendancy (Don Coppersmith is a highly respected cryptographer) but because it was internally too complex, somewhat "inelegant", compared to nice regular structures like Rijndael or Serpent, where proper Science could be made much more easily.