Stay away from fiat puntos. I had one as my first car, they gather oil leaks faster than you can stop them! They are generally unreliable and the head gasket goes on the 8vs too easy. On the later models the power steering fails and said head gasket failure (mk2, not grande).
Corsas are good for first cars, they have very low insurance groups (the 1.2 16v models). Fairly reliable and great on fuel.
Fords are good, like ka's, nice refined engines and are ecenomical.
A good tip is go on to parkers.co.uk and look at the low insurance group cars, goes from 1-20
My fiat punto was group 4, my 1.6 golf mkiv was group 5 and my current ford focus 1.8 tddi is also 5. I'm paying £1800 per year on my own policy tpft. Not bad for my first year driving at 18 I'd say!