I'd say the Panda. Low running costs, very reliable, cheap to insure, relatively safe in Eleganza form (probably would have got a 4* NCAP if that spec had have been tested), well equipped and you'll likely have no trouble with getting pulled over by the Police unless you're driving like a total tool.
The two older cars are likely to be much leggier and need a lot more care, attention and money thrown at them to keep them going. Not to mention the fact they'd likely crumple like a wet paper bag in an accident...which could well happen seeing as you're a new driver (nothing personal, just statistically).
As for the Grande Punto, I don't think they're as well built or as reliable as the Panda, though I'm certainly no expert on them. If you're buying from that class of car (B segment), getting a GP over a mk7 Fiesta is a pretty questionable decision, the Fez would be a far superior drive. IIRC, the GP shares a lot with the Corsa D (as in mk4, not as in diesel), and they're pretty awful as a driver's car (a friend as a 1.3CDTI Corsa D, which is a decent little Fiat engine placed in an otherwise average car).