IMHO:
The A1000; the most advanced machine of it's time
The A500; the best price/performance of it's time
The A2000; the best upgradeable machine
The A3000; heavily equipped with kinda everything
The CDTV; the best design
The A600; too late, but really nice small, expecially considering the A600HD
AGA just came too late, but nevertheless, practically beseen, you're best off with an AGA machine (a towered A1200 with a big huge cheap ide harddisk and an accelerator I think is the most realistic option)