I've got FMS (Free) and a cable I I got for $19 here http://www.mattclement.freeservers.com/fms/fms.html
I've also flown just about all the sims at club meetings or club gatherings. Personally, unless your really into the computer thing with great graphics and stuff like that, FMS is perfect for fine tuning your reaction responses and directional control as well as getting your "fix" on a rainy day. The amount of money spent on the comercial sims could be spent on more flight packs and engines and stuff like that.