Thanks for your response. I want to lift it because I keep taking it camping/off-roading, etc and I find I don't have enough clearance to go where I want. I'm not sure yet how high I want to lift it. I don't really care about the parking lot appeal. I'm lifting it more for utility than anything.
I am also planning on putting bigger tires on once I lift it. Any idea of a good combo to put together on lift and wheel size? I could use a good recommendation on lift kits and tire sizes. I probably wouldn't go any higher than 4" total.
For what you describe, the tire size will be key.
You can fit 33's on it stock, with no lift, right now for example.
If you want taller than 33's, you'd add a BODY LIFT (BL).
For the 2005+ X's, a 3" BL allows 35's, but there is some minor front wheel well trimming....and some front diff durability concerns with larger than 33's.
Depending upon your budget, to handle the 35's, you can swap on some parts from a Titan to replace the Xterra parts to address the diff/axle strength as well as to add some more wheel travel....or wing it with the OEM parts and a judicious go go pedal.
The X has IFS, so, the upper control arms don't allow wheel alignment/avoid coil bucket bang over ~ 2" - 2.5" of lift (SUSPENSION LIFT), so to go higher in SL than ~ 2.5", you would get a set of aftermarket UCA that would allow about 3" or so of total lift.
If 2.5" of SL is enough frame clearance, then all you'd need are either coil spacers or taller coils in front and longer shackles and/or AAL in back.
The rear has a live axle, so its more straight forward to modify.
The longer shackles add lift and soften the ride, and, due to the longer shackle swing, also add wheel travel/articulation.
AAL add lift by making it take more force to compress the suspension/bow the pack...so they stiffen the ride/rob wheel travel/articulation.
The X works best with a nose down rake, so "Leveling Kits" sold to unsuspecting newbs are a hot business but not what you want for functionality.
The S and X came with 265/70/16 (Long Trails for example). That's a ~ 30.6" diameter tire.
If you went up to a 33" tire, say a 285/75/16 or 305/70/16, etc, that would be an increase of ~ 2.4" in diameter, or, 1.2" in radius.
So, 33's net you about 1.2" of lift/ground clearance all by themselves, and they fit a stock rig.
If you did a 2.5" SL on top of that you'd be increasing your frame clearance by ~ 3.7" from where you are now.
As you will never lift enough to never hit, skid plates are the most practical solution...starting with rock rails/sliders.
If you let us know your budget and time frame (Down time to do mods, etc...) and if you would do it your self (These are driveway mods) or want to hook up with some club members for a "Mod Day", etc...we can make more specific suggestions as to good options that make sense for what you are trying to accomplish.
To give you some perspective, here's a recent vid of a guy with a 2" BL + 2.5" SL and 315/75/16's:
http://www.youtube.com/watch?v=oCbeqsnZ56M&feature=youtu.be