My favourite is the A1XE G4. Fastest Amiga ever built,
At the risk of starting a flame war, that's not an amiga in the strict sense any more than the Pegasos 2 is, nor any more than an Amithlon box, for that matter. All three run OS-friendly classic 68K software and all three can make use of machine native code for various time consuming OS calls.
Which is the fastest then?