Microsoft FS X will tick all the boxes, provided it is upgraded to what is needed.
For the UK, there is a complete set of photorealistic scenery available as an addon (plus as well for Germany and Switzerland and other areas) which will require massive amounts of harddisk space but are worth every penny if you fly VFR.
For the UK likewise, there are tons of airports available, some payware, some freeware such as the excellent smaller airports by Alf Denham (find his work at AVSIM) .
Likewise, there are hundreds of airplanes, you will likely find almost your exact trainer in some form or the other.
If you want to profit from this, fly the FS plane according to the same checklists and procedures you'd fly the real plane.
Of course, a proper set of flight controls are essential. Not all of them are good, as it has been said here before, see that you get one which has no "center point" detent.
What is very helpful is a eye tracking device called Track IR. It fits to your baseball cap and will allow you to move the screen view by moving your head. While it is by no means the same as a 180 degrees visual, it will do the job much nicer than people might think. I had one of those almost forced onto me by a friend of mine, but never ever not even once looked back.
I had a hiatus from flying for almost 10 years due to financial and professional requirements. When I came back, the fact that I have logged well over 10 k hours on FS (from 98 to X in the mean time) helped tremendously to cut short the re-training time. Navigation, procedures, e.t.c. came back as if I'd never left and I was happy to train for my flight test using a very similar performing rendition of my Mooney plus a photorealistic Switzerland Pro X Scenery, on which it was no problem whatsoever to find even the most "obscure" VFR reporting points.
For IFR or if you have one of these, I'd strongly recommend the phantastic Garmin 430/530 simulators by Reality XP. Realistically, you don't have time to train those in the air, but with these gauges, which can be built into any existing FS aircraft, you can at leisure play around with these devices and figure them out, while in "flight" rather than a "dead" simulation which is what you'll find with the stand alone Garmin sim.
Have fun.
For those of you who are critical of those sims, go see a properly equipped one. You don't use Windows "naked" either, do you? You buy office programs and other stuff, because the basic program is not enough. Well, it's the same in FS. The FS Box per se is but an operating system, it's the addon products which will make or brake what you can do with it. I've "converted" several die hard deniers of PC based flight sims in recent years, most of them FI's or TRI's. And with any tool you use, it's up to you to use it well or bad, just as you can use Internet Explorer to either surf pprune or youporn. Your choice.
