I use RouteFinder (Free). Enter a Departure and Arrival airports and then press the Find Route button.
This does not give you the SID or STAR, you have to work them out for yourself.
Here is what it gave me for a flight from JFK to LAX:

KJKL DCT DACOS J78 IIU J8 STL J110 TRAKE J134 ELSTO J19 SCAWT J110 ALS J44 RSK J64 TBC J128 PGS STAR KLAX I did a typo. It was meant to be JFK to LAX and some how I enter KJKL instead of KJFK. Sorry. :-[

Here it what it should have looked like:
KJFK DCT LAURN J42 RBV J230 BEETS Q480 VINSE J110 LEJOY J230 AIR Q480 ZANDR J110 BOWRR J80 EMPTY J110 CREEP J80 FYLLS J110 VHP J80 MCI J24 SLN J102 ALS J110 RSK J64 TBC J128 PGS STAR KLAX
DCT = Direct

I also use Flight Sim Commander 9 to create the route by just pasting that line into the route (I remove the DCT and STAR from it). I then mess around with SID and STAR (trying different ones) to figure the best ones for my departure and arrival. The SID, STAR and TRANSITION that can be added to the flight plan in FSC9, has made it a very good tool for creating routes for my CS aircraft. FSC9 has a link to RouteFinder Free (opens its own page within FSC) so you can search out a route.

Mark