Liberties have a ton of problems, the 3.7L V6 and 42RLE transmission both have major reliability problems and newer Liberties (KK) seem to be poorly assembled.
Wranglers are decent, 2012 and newer with the 3.6L Pentastar V6 or 2006 and older with the 4.0L I6 (TJ/YJ) would be recommended (note: 4-door wranglers weren't available until 07), 07-11 Wranglers tend to have reasonable reliability (particularly with the manual) but the 3.8L ("mini-van") V6 tends to be underpowered.
WK2 Grand Cherokees (2011+) are decent if you want the luxury features it offers and don't plan to beat it too hard off-road.
XJ Cherokees (84-01) are very reliable and capable off-road if you don't mind an older vehicle, (91-99 tend to be the most reliable).
Jeep Model Glossary:
XJ: "Regular" (Not Grand) Cherokees. (84-01)
YJ: Wrangler 1st generation (87-95)
TJ/LJ: Wrangler 2nd generation (97-06), LJ is a stretched wheelbase version (04-06)
JK/JKU: Wrangler 3rd Generation (07+), JKU is the 4-door "Unlimited" version
ZJ: Grand Cherokee 1st generation (93-98)
WJ: Grand Cherokee 2nd generation (99-04)
WK: Grand Cherokee 3rd generation (05-10)
WK2 Grand Cherokee 4th generation (11+)
MJ: Comanche (an XJ Cherokee based small pickup)
KJ: Liberty 1st generation (02-06)
KK: Liberty 2nd generation (07-12)
SJ/FSJ: Full Sized Jeeps (Wagoneer/ J-Series truck/ pre-84 Cherokee)
CJ (pre-Wrangler "Jeep" Jeeps, pre-87)