I LOVE this car! I lost my job and have driven brand new cars over the past several years, most recently a loaded '08 Honda Accord EX-L with navi. I like my "new" Volvo more than the Honda.
I've owned two other Volvos; a 2005 S40 (nightmare, it was always in the shop) and a 2001 S60 (loved this car and wish I would have kept it). My 97 850 is fun to drive, unique and feels solid and safe -- and I know it's safe. Have you seen that Youtube video where they run it off a cliff?! I plan to maintain my 850, money-permitting and hoping nothing major goes wrong, and drive it until at least 300,000 miles! I know it's capable of it.
There are things that you should expect to just "let go of" when purchasing/owning this car. Things will rattle, interior light bulbs will burn out and you'll be replacing exterior light bulbs often if you utilize the daytime running lights (all lights operate, not just the headlights at a reduced light) feature. Safety first.
I'm quite handy when it comes to fixing some of these more minor pesky issues like dash bulbs burning out, etc, so that doesn't bother me too much.
All in all, this is a fantastic car and my favorite along with my S60. It's fun to drive, looks great and unlike anything out there now, has great handling, great get up and go power, comfortable seats and an engine growl that just makes it fun to step on the accelerator!
If you're buying a used one, be sure to get service records if possible and follow your gut instinct. You do not want to buy one of these cars if it hasn't been well maintained. Also, be sure you replace the timing belt on the recommended 80,000 mile frequency or you'll be looking at having to replace/rebuild the interference style engine.