Depends what kind of PC you have. Can you run X-plane 10 or P3D at full settings? If no, then go with Xplane 10 or FSX. If you can, then I highly recommend P3D. Much more visually realistic. Xplane uses a "plasuable" engine for its scenery, and the stock airports have little to no detail. While the planes fly more realistically as a whole, some of the good add-on planes for FSX/P3D fly very realistically as well, and the panels are usually much more realistic and more systems are simulated vs. the add-on planes for X-plane usually. Plus way, way better free stuff out there, and spending a little money(like getting the FTX add-ons from a company called Orbix) can make your sim visually ultra-real in one install.
I just finished upgrading my PC to a monster with a top of the line graphics card, 32GB of ram, great CPU, and run it off a 45 inch TV with using a mix of the Saitek X52 throttle(the joystick in the pack sucks) and a Thrust Master T-16000 joystick(just AWESOME response and can be used left or right handed) on either side of me in a gaming chair angled up at the TV. Still get 30+ frames per second. It's intense. Like...intense. P3D v3(newest version whichc is very new, worth noting here that every version is a new game just like FS2000, FS2002, FS2004, ect so you can't just update it) has SO much detail and simulates the physics of flying much more realistically than FSX did(mostly noticeable in ground effect and slow flight). As a training tool, it is priceless. I like to take a Grumman Tiger over downtown SF, kill the engine, and figure out where to glide. The add-on scenery simulates the building heights, trees, and terrain well enough to make it very reasonable. Here is a video of the add-on SF scenery I have as seen in P3D at full settings. I think this is an older version as well, looks even better in v3.
I own X-plane 10, it looks cool enough, but the crash detection is very unrealistic(see how hard you can slam planes down) and it simply just doesn't look as cool. Plus it's much harder to mod, in my experience. I also much prefer the Microsoft/Lockheed interface for everything.
You practice with a CRJ in FS?
You know they send us to a Level D sim, right? It has the actual cockpit and everything, they're really advanced these days.
I know right, what's the point of practicing on your own computer with a working virtual cockpit that simulates all the systems of the plane you're hired to fly and going to spend the next few months learning to fly to make training, you know ,easier? Go ahead and hate on him, I just wish I could be as cool as you. But I guess I'll always just be a loser with his flight simulator. Not like flight-sim add-ons are a multi-million dollar industry or anything, who would want a piece of that nerdy pie when they'll be judged by studs like you?