My father swears by Flight Simulator. He loves to fly small aircraft as and when he can, but the trouble with this pastime is that not only does it require fairly decent weather (in this oft temperamental temperate clime) but unless you own your own plane it's not exactly cheap. His response to being literally grounded over the years has been to lose himself on occasion in this series, such is the level of detail and technical accuracy of the series (not to mention its exponentially smaller price tag), of which X is by far the most accomplished package to date.
You can pick up Microsoft Flight Simulator X Gold Edition, which combines the Deluxe Edition of the game and the Acceleration package into one big happy bundle, for £15.93 at The Hut at the moment, saving you a over £1.50 on nearest competitors over at the 101cd group of sites. Zavvi have it for just over two quid more, but the APRIL2 voucher code will actually bring it down to just a few pennies behind this price, although The Hut is still the cheaper merchant for this particular product.
Flight Sim X Gold is pretty much the ultimate package really. Whilst the core mechanics remain relatively unchanged, apart from in creased detail in almost every aspect of the game, the graphics are better than ever, airport vehicles potter around you and the airports themselves now offer jetways. The Deluxe edition boasts an on-disc Software Development Kit, 6 more aircraft than the Standard Edition (9 if you include the lot from the Acceleration pack), and the ability to play Air Traffic Control in relation to other online users. There are 38 detailed cities compared to Standard's 28 too. Acceleration adds even more into the mix, offering online air races which are a hell of a lot of fun!
The important word here is 'Simulator'. This doesn't offer you arcadey accessibility nor does it particularly invite the casual gamer to the table, but it does provide a genuinely rewarding simulation of what it's like to actually fly a plane. If you have a computer powerful enough to run the game at its finest - and possibly add some of the many map packs available into the mix - then you will not find a closer approximation to soaring through the skies than this.
Thanks to millarcat at HUKD