If you buy Tamiya's Willys MB Jeep, kit #35219, you will be pleased. It is one of the finest Jeep kits produced to date. It runs about $15 or so and comes with a driver's figure. It is the tops in WW2 Jeeps.
There is a couple of older Tamiya Jeeps, one is the SAS Jeep with British soldiers in Bedouin gear and another that comes with a trailer. These are older kits and not as nice. It is best to avoid these as they are rather dated.
If you'd like to do a Korean War era Jeep, Skybow makes the M38A1 and M38A1C with recoilless rifle. Both of these kits are top notch and you will not be disappointed. AFV Club now reboxes the M38A1 Jeep.
If you like a Cold War Jeep, Tamiya's M151A2 series is decent. Academy makes exact copies of these Jeeps and have also released several of their own updated ones, both the Vietnam era M151A1 and the more modern M151A2 (we used these into the late 80s and I even saw National Guard units with them in 1992). The model manufacturers refer to these Jeeps as "MUTT"s (military utility tactical trucks), but we just called them Jeeps.