Audition, audition and audition some more. Then remember that whatever you're listening to will sound very different once you get it home. This was easier back in the day when audio shops were more common than they are now. Regardless, take your time, check out as many rigs as you can, do your homework and buy what sounds good to you. My rule of thumb is that if it isn't fun, it isn't worth it.
Good luck & happy listening!
Good luck & happy listening!