A vote for Elite from me.
There are two things I find particularly useful. Firstly, you can set varying levels of turbulence, which is useful for keeping the scan sharp as you have to be much more attentive to attitude and level. Secondly, you can speed everything up (including the clock and the timer on the ADF so everything stays consistent). That is great for training - if I practice a procedure when everything's happening 10% faster, it then seems much more relaxed when I come to do it in the aircraft. It's a lot easier to stay ahead of the aircraft.
The graphics are pretty basic, which means I can run it fine on my laptop. All I need is a pretty basic joystick. It's pricey for what it is, though. Although considering the use I've got over the years, it's been worth it.
I've also used the old MS flight simulator. I never found that very useful until I got the DreamFleet Piper Archer add on, which was stunningly accurate. I used that before I ponied up for Elite. It was still very useful for the occasional VFR approach which needed a bit of forethought - Saanen, for example.