I have a 2000 Jetta TDI with 86,500 miles on it. I'm a 30K mile a year commuter and I love this car!. It is very comfortable and roomy for a compact ( I'm 6'1", 245lbs.), more so than I think the hybrids would be. The only problems I have had are the drivers side mirror does not defrost as well as it used too, and the heater fan whines a little when it is really cold. Since I'm too cheap to pay to fix it, I just live with it. One thing I would do differently is get the leather. I got the black cloth, and I think it manufactures lint! The leather is so much easier to keep clean.
I'm just getting ready to change the timing belt. VW reccomends checking it at 40K and changing by 60, but when I talked to the dealer he said I could go up to 100K (because of the power train warranty), once again the cheap [censored] mentality kicks in. I've gotten quotes from several dealers, and they all come in around $500.
It's been cold here lately, and I have had no problems with starting at all. Some mornings it has been at 0 or below.
The performance is amazing out of a 90hp diesel. I have a lead foot and typically cruise at 80mph and still manage 47-48mpg. The car gets up and goes at a respectable pace and drives very nicely on the highway. It also handles well in the turns. The 5 spd manual works well. You will get better mpg with the manual. Oh yeah, and right now the price of diesel is at or below the price of regular gasoline around here. About two and a half years ago it was $2 a gallon, but overall I think my fuel cost is well below the national average. I love having to only fill up once a week!
The car is a little pricey for the size, but I don't think you can get a better overall package with regard to size, fuel economy and performance. I bought at the peak of Jetta mania, so there may be better deals out their now. I also bought when there was only a 2/24 warranty. I believe that they now have a 4/48. I could have used that about a year ago to fix my mirror problem.
I would love to see a Passat diesel. With the family growing, the Jetta can get a little cramped when you add one of those monster car seats into the mix. I saw on the German VW site that they make a 6 cylinder TDI, that would be awesome.