[jtkung]

This is yet another ripe area with so many options.  People talk a lot about the guitar shape, tonewoods, neck, fingerboard etc all affecting the sound. I do not doubt that this is true. But a lot of these have a smaller effect compared to:

• Pickups
  
• Guitar Amp
  

The pickup really has a profound effect on the tone, as this is the sensor used to sense the vibrations.  And how you formulate the magnets, windings, etc. or how you detect the vibrations make a huge difference in tone.  Just compare a single-coil with a humbucker, P-90, gold-foil, or more modern Lace Alumitones or EMG actives and you should be convinced.  The sounds are night and day.  There are also many great pickup makers out there -- from mass market to boutique.  Another renaissance. 

In terms of amps ... they make a huge difference. Probably the most, depending on the type of music you play. If you play clean or bluesy, the guitar can really be discerned, and the amp contributes a lot but does not overpower. As you increase the gain, it gets harder to tell what kind of guitar is used. For example, if you listen to Eric Johnson's great CD, Ah Via Musicom, you can tell it's a Strat used on the cleaner, bluesier tones. But at highest gain, he actually uses an ES-335 on some tracks. He uses a Strat also on high gain solos, yet you would be hard pressed to tell which guitar he is using. And those guitars are very different in sound when played clean. The amp is what you are really hearing.

I'm really liking the boutique guys for pickups. Lace, Holmes, Bare Knuckle,  Fralin, Lollar, Harmonic Designs are just a few.