KJ Tires

There were two stock tire sizes in 2004 (probably the same for other years)

215 75 R16
Sidewall: 6.3in
Radius: 14.3in
Diameter: 28.7in
Circumf: 90.2in
Revs per Mile: 703
235 70 R16
Sidewall: 6.5in
Radius: 14.5in
Diameter: 29.0in
Circumf: 91.0in
Revs per Mile: 697

If you want to see the difference between tire sizes, check out the tire calculator at miata.net

I'm planning to purchase a set of Bridgestone Dueller Revo's for my liberty.
235 70R16's are only $118 at tire-rack. I'll probably buy locally to keep mounting costs down.
I've only read good things about these tires, and have been wanting to get some FOREVER.

BF Goodrich All Terrain T/A
I've always had good luck with these tires. They've gotten a bit pricy, but it's a good quality tire.
They run very well in most conditions. I never managed to make one go flat.

These are sexy looking! They are great offroad, but in the rain on road not so much.
Good truck tires, but noisy so I wouldn't use them on a primary vehicle.

Spiffy tire chart from jp mag.