I am going to take a stab and guess that this is a symptom of recording your vocal whilst playing the guitar at the same time
To get an "intimate" vocal you really need to get "up close and personal" with the mic
e.g for the style you usually perform I would be expecting you to be within 6inches or so to the mic - ideally with a pop filter inbetween
It can usually be difficult to capture this consistently whilst playing guitar at the same time
Here are a few key concepts at their simplest - RAM is spot on when he says it is a combination of many factors but to make some very wide generalisations...
The STEREO field is an imaginary semi-circle going from your left ear, in front of you, and then to your right ear
You use the PAN control within your DAW to place your MONO tracks somewhere in this stereo field
STEREO tracks can be tricky as a lot depends on how it was originally recorded so a simple "PAN" control may not have the expected effect - i.e. a STEREO track already contains a mix of 2 mono tracks (a left and right channel) so panning a STEREO track will not behave in the same way as a mono track as it may already be panned within the STEREO track itself!
e.g. I could email you a STEREO track of me playing guitar and singing - I may have chosen to pan my guitar to the left and my vocal to the right when I create the STEREO track
If you then try to pan this STEREO track in your project it will not work as you expect as it is already "skewed"
This is why it is always best to work in MONO tracks when collaborating - i.e. sending each other MONO Tracks - if you have a STEREO track treat it as 2 MONO tracks panned hard left and right
REVERB can be used to control the distance from the listener
e.g. less reverb = more "up front" and more reverb pushes things backwards
It is also possible to get some pseudo "up and down" vertical depth by using high eq to "raise" sounds and low eq to lower sound - although this is much more subtle
The equipment is also really important before you even get to compressors etc.
The mic and pre-amps are critical to get that "professional" sound
A large condenser mic would be a good bet for your vocal
You could look in to a reflection filter but they are quite expensive so I am not convinced they offer a good "bang for buck" - although to be fair I have never used one
http://www.gear4music.com/Recording-and-Computers/sE-Electronics-Reflexion-Filter-Pro-Portable-Vocal-Booth/6L8 Just a few "off the top of my head" thoughts - hope this helps