1. Advantages: Medium consumption, average price in parts.
Disadvantages: Not much comfortable not bad either. It could have some problems since italian engines does not hold through years. (same goes for other engines too)
2. Advantages: Medium-high consumption, cheap parts & they can be found easy.
Disadvantages: comfortable (for 4 passengers), it has a strong engine (pretty good at road - also it doesn't have many problems through years)
3. Advantages: Low consumption, cheap parts but it's not easy to find them since it didn't had much sales.
Disadvantages: 50% comfortable, not enough spaces. (Trunk is fine)
4. Avoid it in any case, its engine isn't good. Also, it's not comfortable at all.
5. Advantages: Medium-high consumption, cheap parts & they can be found almost everywhere.
Disadvantages: Not much comfortable not bad though (Trunk is kinda small), it has a good and strong engine. It handle almost everything.
6. Advantages: Low consumption, cheap parts if you need to replace anything.
Disadvantages: Not comfortable, not enough power (for abrupt streets), not enough spaces (if you have a family) in case of a road trip.
In general (based on the age of the cars(2001)), i'd say that most of them if not all aren't tubro so they have smaller consumption than newer models.
Except golf and peugeot 206 , the rest of the cars have engines that have or will have(soon enough) some problems. These two models have a medium to high consumption (this is based in the way that you drive) , but they have cheap parts which can be found everywhere. Peugeot has more power at its engine and it is slighter lighter than golf. Golf's aerodynamic is better and also driving experience is much better. Acceleration & top speed is almost the same.
I'd suggest golf but peugeot whould be bad either.