I know the newer 350's are nice and they're coming out with a 370 that will have more power if you're willing to wait and get brand new.
I had an 04 350z and it was one of the earlier ones so it was still fun, but to be honest I think the car is a little unsafe (the huge blind spots). It's a fun car to drive, but it's really easy to lose sight of a car next to you. Also, I think it's a tad easy to lose control too because when I drove one I got back to our lot I was swinging the corners even though I wasn't gassing it all that much, but I'm sure that could be solved with simple sticky tires. In my opinion, I just see too many Z's now a days and I don't know about you, but I just want something more unique.