Stay away from the 2001 V70. The P2 V70's are very good cars, just look for a 2002+. The '01s are bereft with transmission and electrical issues, and if it hasn't had them dealt with already, you're going to be looking at them in the near future.

Really, it comes down to what you like. Test drive them all, and then make your decision about what car you liked the best. Then start ranking them based on things like service records and what maintenance (timing belts, etc) needs to be done to them.

Personally, I like the way S60's drive, they're more refined than the S70's like mine are, and not as huge as the S80. They're pretty much the same across model years. You could probably talk that price on the 2003 down to 8-9K though, 10 is just too much. If they refuse to budge, I'd look elsewhere. The S80 T6 is a NICE engine, but they don't mind eating gas. I believe by 2004, most of the S80's reliability problems had been worked out.