I'm definitely planning on keeping it stock. When I get the itch to mod something, I've got my Wrangler.
However, if I was going to do something it'd be a tough call.
To Raise: On the one hand, I'd want to raise it several inches, drop the 20" rims for some 16 or 17" cheap aluminums and toss on some mudders after hacking off chunks of the wheel well and that lower air dam. That'll get me some decent extra clearance when going off the beaten path. I could throw on a brush guard and tack on additional lighting, maybe a winch. The downside is that there is no getting around the fact that the Nitro is not designed as a dedicated offroader, the most noticeable testament to that is the lack of 4Lo.
To Lower: The Nitro can look pretty sick lowered. Get some bling-bling rims and nice tires, toss bzaudio's system in the back and ground effects in the undercarriage. Tint out windows. Find a custom shop to fab up a body kit and snag some euro-style lighting. Downside is that you lose any shot in hell of taking that thing off the road, not to mention heading to home depot and loading up on concrete and supplies for the next project.
Stock: Boring, but cheap. I'm a big fan of cheap.
I think the Nitro is one of the few cars that would look really good either way, as long as you commit to it.
- Aaron