I bought a 1991 VW jetta non-turbo diesel for exactly that reason. I love my diesel truck, but, for commuting around town or even trips where i'm not hauling anything I really like my little jetta. I've driven it across the country many times, to texas, florida, missouri and everywhere in between and it has never let me down. The 91 is nice because it has more creature comforts than previous models, yet, it is still a non-turbo mechanically injected diesel. It's less than 60 hp so it's not fast, but it will cruise just fine at 75-80, and has decent enough acceleration that, once you're used to it, is perfectly manageable; I may not be passing everyone, but it keeps up with traffic just fine. Being a non-turbo I get great mileage, 50-60 on the highway, and close to 50 in town. the '91 is a nice model with decent passenger space, a huge trunk, and still maintains the drivetrain simplicity of earlier model year jettas. When I was looking for a smaller diesel vehicle to drive daily instead of my truck, I specifically sought out the '91 model year jetta; I bought it in mint condition sight unseen, picked it up and immediately put over $1000 into it to bring it to like new condition with regard to handling and durabilty. I replaced the battery, water pump, head gasket (added studs), all belts and hoses, bushings, cv axles, ball joints, struts/shocks and mounts etc. The car handles like new, drives like new, and looks like new for less than $2200 total cost. Parts are very cheap for '91 mark II jettas which allows you to replace things without feeling too badly. I also have a 1995 E300 diesel that I absolutely love, but would not reccomend as a daily driver for great mileage (parts are expensive, needs special tools to work on, and averages only around mid 30's mpg instead of the jetta's 50+ when properly tuned).
BTW, if you're looking seriously at putting a small diesel in jeep etc. and have a goal of reliability and good mileage, I would avoid going after too much power. In fact, I would avoid anything with a turbo, it reduces your fuel economy (not by much, but if you're not going for power, why bother). With an N/A diesel, you don't have to worry about EGT's, you get better fuel economy and generally better initial throttle response, and you've eliminated an additional area of failure. Without spending some dough, the jeep's drivetrain will be destroyed by a diesel producing much power or torque, unless you're looking for a money pit/big project, stick with a small, non-turbo diesel producing less than 100hp and you'll be better off.