Alternate conclusions of The Usual Suspects

There aren't any.

In fact the film goes out of its way to make it clear that Verbal is Soze by including:

1. The scene during the takedown robbery where Dylan hesitates to kill the driver and Verbal does it in cold blood.
2. The scene on the docks when someone asks what language the crew members are speaking and Verbal answers "Hungarian."
3. The fact that of all of gang members, only Verbal doesn't "know" who Keyser Soze is and apparently has never heard of him.

A careful review of the film will demonstrate that Verbal is Soze from the beginning and the film throws various MacGuffins in the way to prevent a less discerning viewer from realizing that early on.

I have a theory that the real Keyser Soze is none of the five Suspects, but actually Kobayashi (or at least, the person Verbal talks about as Kobayashi and who is played by Pete Postlethwaite).

The main evidence for this is: it's Postlethwaite who picks up Spacey at the very end of the movie.

Now, we only saw this person before in the story woven by Verbal to Kujan, so it's suspicious right from the start, because we don't really know how much of it is true and how much is fabrication. We know that the name Kobayashi is made up, so was there really ever any lawyer who threatened the Suspects to take on the Hungarian boat job? Maybe it was Soze himself?

Verbal (Spacey's character) is just his very trusted accomplice, or "front", to the point where if someone around the world thinks he knows how Soze looks like, they think of Kevin Spacey, not Postlethwaite. The fact that Keaton admits knowing Verbal for several years aids this theory, because would Soze keep appearances as a low level criminal in New York for years?

For me this seems legit because:

• at the end we see that Kovacs (the burned Hungarian in the hospital) gave a pretty accurate description of Spacey as Soze. Would the real Soze allow such a gaping hole in his plan? Wasn't the whole attack on the boat for the sole purpose of killing the one person who knows how he looks?
• on the boat we see the that person screaming in horror and identifying Soze before being killed by him (signature two shots in the head). But we don't really see who killed him. And...
• ...we don't really see who kills all the other Suspects on the boat. We only see their reactions, and still it's all told via unreliable narrator. It might be a non-crippled Verbal, which would prompt some of the reactions (McManus' "Strangest things"), but sudden appearance of a seemingly meek lawyer as a brutal killer would possibly warrant similar reactions.

We don't know if it was Verbal or Kobayashi killing everyone on that boat. Might be both of them, might be just Verbal. Even if it was Verbal who was identified as Soze both by the guy on the boat and the Hungarian in the hospital, this all might be a Prestige-style elaborate ruse to throw off anyone claiming to know how Soze looks by hunting those who only know the false Soze face (i.e. Verbal), just to keep appearances that this is the secret.

This way even with a screw-up like a memory portrait at the end, the world would still have the false face of Keyser Soze.