AshDVS;19482 wrotePulsar or Corolla of that same mid-late 90s/early 00s era would be my pick for sure.
If you must have a volvo, a very late 240 is what I'd do.
Cheap to buy, easy and cheap to fix/maintain, reliable.
I'd personally avoid any 850 or S70/V70 thing or even S40 - student cars typically tend to get neglected or poorly maintained, so this is why I'd not suggest one.
I wouldnt go with a 740 - You really dont want them to be teased by their classmates. :)
Unless of course they are studying education; may as well get em ready for abuse early