Hey Brooski, First Great looking X.
There are literally hundreds of mods from Mild to wild when it comes to your truck! when It comes down to it you need to decide exactly what you want your truck to do and how you want it to look. There are tons of amazing looking and highly modified Xs on the forum! My suggestion would be to read through a few build threads and see what stuff you like and what stuff you dont think work for you.
On the first gen Xterra most guys remove the rear sway bar along with the steps and flaps(looks like you said you did that). It is a known issue that The sway bar will contacts the rear shocks when doing any real off roading.
You can pull the molding off the sides to get a cleaner look.
Some guys pull the grill and all the other plastics and paint them black or do tons of other paint combos.
If you are looking to lift the truck a little you can do a PML (Poor mans Lift) which includes tightening your torsion bar adjusters and adding rear lift shackels for a couple inches of lift.
New Bilstein shocks 0" to 3" of lift
Click here can be added for a great improvement in ride quality.
Volant Makes a really nice intake system
Click here to check those out.
New roof racks, bumpers, Tire carriers, LED Lights...The list can go on forever!!
These are just a few Ideas, But like I said before, its all about what you personally are going for with your truck! There is tons of info on the site. If you find a build you like shoot that person a PM and ask them a few questions on what the did. All the guys on this forum are always willing to help!
Also I am always willing to give you any advice you may need. I have owned a first gen and now own a second gen and have had the mod bug for a Looooong Time..
Hope this helped! happy modding!!