RE: Solstice2006, good point about the premium gas in the N/A 2.4, this is a head-scratcher.
I like the fact that this is a 'safe, small car' - there are quite a few folks who perceive small vehicles to be unsafe, but a small "Volvo" may ease that sense of insecurity but still provide the benefits of a smaller car. I think the safest bet in terms of reliability would be a lower-trim non-turbo 2.4i FWD model. With a 2.4 litre engine it should have enough get up and go to move this car around comfortably, and there are fewer worries about expensive repairs to turbos or AWD systems down the road.
My coworker had an S70 that looked like new after 13 years. 317,000 kms, one set of brakes, factory exhaust, no body rust, leather wasn't cracked or broken. Volvo makes a well-built car, that's for sure.