First a small amount of background. I'm in my mid-30's now, and presently I drive deliveries for a living (while building my small business).
I think to know where you're coming from you have to know where you've been. The vehicles I've driven influences what you buy in the future and what opinions you have any why. I've daily driven the following vehicles in my life (for whatever purpose): '96 Saturn SL1, '96 Buick LeSabre, '66 Ford F-100, '03 Mazda B3000, '96 Honda Civic ex, '85 Mazda Rx-7, '88 Toyota Supra Turbo, '12 Toyota Corolla S, '04 Land Rover Discovery SE7, '13 Subaru Outback, '86 Toyota Land Cruiser, '93 Toyota Pickup, '07 Chevy Aveo, '07 VW Touareg. I'm sure there's a few I'm forgetting.
I'll hit on a few points about the Volvo 850's/X70's that I love.
I drive literally for a living. I put about 3000 miles a month on my car. So that seat, and driving position has to be comfortable. The p80 seats are nothing less than heaven. When I do long road trips, I always rent a car. They have been giving me some of the "nicer" newer cars to rent lately, and I have to say that aside from the Cadillac XTS that I drove, they we're all terrible. Especially those Chrysler seats. Yuck.
Sure the cup holders suck, but do you really need to be drinking while you're driving anyways?
Another comfort thing that people don't think about is viewlines, and blind spots. Newer cars have these massive A, B and C pillars, padded with airbags. Well, I can't see around them! The A-pillars on the p80's are thick, but have such small blind spots, that its super rare for there to actually be a car in my blind spot. Who needs blind spot indicators when you can actually see around your car?
2: Easy to work on
I have owned a few cars that were not easy to work on. My 850's were none of those. Now that I've owned a Volvo for about 8 years, I know all the ins and outs, who to buy from, what parts to get from where, etc. That is unbelievably valuable knowledge. Nothing on my two p80's has been particularly difficult to remove and replace. A few things have been stuck, and needed some persuading, but nothing has ever been so seized into place that it couldn't be removed with some effort. Save two things: A/C expansion can, and my thermostat housing bolts.
3: Storage volume
Both my wagon and sedan have had the storage volume of much larger vehicles. My sedan can hold 23 bags filled with five 14" pizza (with boxes). My wagon could hold 34 bags (there are pictures of these things in my Herman build thread linked in my signature). I have picked up large armoires in my wagon, and countless amounts of furniture, parts, and free stuff off craigslist and the like. My wagon helped me move from Boulder back to St. Louis this last time around.
4: Helpful community of Volvo owners
I cannot stress this one enough. It's fine to drive a great car, but if all of the repair forums are full of jerks, it's not a car I am going to keep for very long. MVS (yes all of you on this board)
and Robert Spinner (RSPI\RobertDIY), keep me coming back every time I have an issue. Guys who drive cars like supras and civics argue about who has the best turbo build, and what the best techniques are to build and engine, and quite frankly use demeaning language to do it. Guys who are american car enthusiasts aren't always the best communicators, so the help you get is vague, and often wrong. Land Rover repair is almost non-existent.
But Volvo people? Oh. They are the cream of the crop. Everyone is polite, helpful, wants to learn more, and quite frankly goes out of their way to make sure you got the problem fixed. The worst disagreement on this forum? Oil viscosity. Oh, and fuel rating. Those are the politics and religion of Volvo people. Just don't talk about them.
Robert's videos. When I am nervous to tackle a project, it is so freaking helpful to have a video to watch before I tackle something to see if I can handle it or not. His helpful, folksy way of speaking, and his soft demeanor makes me believe that anyone (especially me) can fix this issue.
5: Great blend between, function, comfort, performance, and economy.
If a car is comfortable, it is probably not performance oriented. If it's functional, it's probably not nice to drive. If it is performance oriented, the economics are going to bite you in the butt (expensive parts, gas, brakes, and tires) But Volvo hit this really nice blend of all four of those categories. Sure I'd love a 5-series BMW or E-Class Mercedes wagon, but the balance will be off.
If you haven't read it yet. Check out my on-going build thread "Herman and Operation 30MPG" It is nothing more or less than a love song for my Volvo. Link is in my signature.