I've had both, after the 3d gen, the Golf is better.
Here's why:
Headlights
Rear headroom.
Outward visibility.
Trunk opening.
If I had to have one car, there is ZERO chance it could ever be a small sedan. There is just too many times I have put stuff in my Golf that would not have ever fit in a Jetta. At least the earlier Jettas still had the same roof line in back, it did not sweep down chopping off the rear head room, and they were still a "3 box" sedan, with lots of easy sight out of the rear window, and had a giant trunk for a small car (actually, the trunk on my A2 Jetta is bigger than my B5 Passat!).
Push mower, chairs, shop sink, a big ZF transmission, and even a 1Z 4 cyl TDI engine... complete, fully dressed, turbo and all, will fit in the back of a Golf.